UNITED STATES DISTRICT COURTDISTRICT OF MARYLAND

(Northern Division)

Master File No. 07-cv-012104FMIN RE SOURCEFIRE, INC. SECURITIESLITIGATION

This Document Relates To: All Actions

JOINT MOTION FOR PRELIMINARY APPROVAL OF SETTLEMENT ANDREQUEST FOR SETTLEMENT FAIRNESS HEARING

Lead Plaintiff and Defendants, by and through their undersigned counsel, jointly move

this Court for preliminary approval of a proposed class action settlement pursuant to Fed. R. Civ.

P. 23 and for entry of a scheduling order to establish a procedure and schedule for the events

leading up to the final approval hearing for the proposed settlement. This motion is based upon

the attached Stipulation & Agreement of Settlement (the "Stipulation"), dated as of February 10,

2009, attached as Exhibit 1, and a proposed Order Preliminarily Approving Settlement and

Providing for Notice (the "Preliminary Order"), attached to the Stipulation as Exhibit A. The

grounds for this motion are set forth in the attached memorandum.

WHEREFORE, the parties respectfully request that this Honorable Court enter the

proposed Preliminary Order submitted concurrently herewith.

Dated: February I 2009

Respectfully Submitted,

TYDINGS •f SENBERG LLP;„.By: AlifrJohn : Isbi er, ederal Bar No. 00639Jaim- W. Luse, Federal Bar No. 27394100 East Pratt Street, 26th FloorBaltimore, MD 21202Telephone: (410) 752-9714Facsimile: (410) 727-5460

Liaison Counsel for Lead Plaintiff andthe Proposed Class

KAPLAN FOX & KILSBEIMER LLPRobert N. KaplanFrederic S. FoxHae Sung NamAviah Cohen Pierson850 Third Avenue, 14th FloorNew York, NY 10022Telephone: (212) 687-1980Facsimile: (212) 687-7114

, Lead Counsel for Lead Plaintiff and the Proposed Class

HOGAN & HARTSON LLP

By: AAAMark D. GatelyHOGAN & HARTSON LLP111 South Calvert Street, Suite 1600Baltimore, MD 21202Tel: (410) 659-2700

Counsel for Defendants Sourcefire, Inc., E. WayneJackson, III, Thomas M McDonough, Todd P. Headley,Martin F. Roesch, Asheem Chandna, Tim A. Guleri,Harry R. Weller, Steven R. Polk Arnold L. Punaro andJoseph R. Chinnici

COOLEY GOD ,' .1411 KRONISH LLP

By:

Robert T. CahillCOOLEY GOD WARD KRONISH LLPOne Freedom SquareReston Town Center11951 Freedom DriveReston, VA 20190-5656Tel: (703) 456-8000

Counsel for Defendants Sierra Ventures VII, LP andTim A. Guleri

DLA PIPER LLP (US)

By:David Clarke, Jr.DLA PIPER LLP (US)500 Eighth Street, NWWashington, DC 20004Tel: (202) 799-4000

Counsel for Underwriter DefendantsMorgan Stanley & Co. Incorporated,Lehman Brothers Inc., UBS Securities LLC, andJefferies & Company, Inc.

COOLEY GODWARD KRONISH LLP

By:

Robert T. CahillCOOLEY GODWARD KRONISH LLPOne Freedom SquareReston Town Center11951 Freedom DriveReston, VA 20190-5656Tel: (703) 456-8000

Counsel for Defendants Sierra Ventures VII, LP andTim A. Guleri

DLA PIPER LLP (US)

By: ksce..;-Jc-tkAdt44s ( -7.David Clarke, Jr.DLA PIPER LLP (US)500 Eighth Street, NWWashington, DC 20004Tel: (202) 799-4000

Counsel for Underwriter DefendantsMorgan Stanley & Co. Incorporated,Lehman Brothers Inc., UBS Securities LLC, andJefferies & Company, Inc.

1

UNITED STATES DISTRICT COURTDISTRICT OF MARYLAND

(Northern Division)

Master File No. 07-cv-01210-JFMIN RE SOURCEFIRE, INC. SECURITIESLITIGATION

This Document Relates To: All Actions

LEAD PLAINTIFF'S MEMORANDUM OF LAW IN SUPPORT OFPRELIMINARY APPROVAL OF SETTLEMENT

Lead Plaintiff Sandra Amrhein ("Lead Plaintiff') respectfully submits this Memorandum

of Law in support of her motion for the entry of an order (i) granting preliminary approval to the

proposed settlement set forth in the Stipulation and Agreement of Settlement dated as of

February 10, 2009 (the "Stipulation"); (ii) approving the form and manner of giving notice of the

proposed settlement to the Class; and (iii) providing a schedule for the dissemination of notice to

the Class and other proceedings required for the Court's consideration of the settlement prior to

the Settlement hearing.'

I. INTRODUCTION

The proposed Settlement now before the Court for preliminary approval provides for the

payment of $3,200,000 in cash (the "Settlement Amount") into an interest-bearing Escrow

Account for the benefit of the Class in full and complete settlement of the Released Claims. The

Settlement is an excellent result for the Class in light of the significant risks Lead Plaintiff faced

in the Action, including inherent problems of proof and possible defenses to establishing liability

and damages at trial. As discussed in detail below, Lead Plaintiff, Kaplan Fox & Kilsheimer

LLP ("Kaplan Fox" or "Lead Counsel"), and Tydings & Rosenberg LLP ("Liaison Counsel")

based on their evaluation of the facts and governing law, their recognition of the substantial risks

of continued litigation, and the anticipated time and expense of litigating this complex securities

action through trial, submit that the proposed Settlement is in the best interests of the Class.

Accordingly, Lead Plaintiff respectfully moves for preliminary approval and submits this

Memorandum of Law in support of the proposed Settlement.

All capitalized terms used herein are defined in the Stipulation.

1

II. FACTUAL AND PROCEDURAL BACKGROUND

A. Procedural History and Description of Lead Plaintiff's Claims

A mere twenty business days after its March 9, 2007 initial public offering (the "IPO")

became effective, Sourcefire announced on April 9, 2007 that weak customer orders adversely

affected Sourcefire's revenues. Starting on May 8, 2007, a number of Sourcefire investors filed

securities class actions on behalf of all persons who purchased the common stock of Sourcefire

pursuant and/or traceable to the Company's Registration Statement/Prospectus issued in

connection with Sourcefire's IPO. By Order dated September 4, 2007, the Court consolidated all

related actions, appointed Sandra Amrhein as Lead Plaintiff for the class and appointed Kaplan

Fox as Lead Counsel and Tydings & Rosenberg LLP as Liaison Counsel.

On October 4, 2007, on behalf of Lead Plaintiff, Kaplan Fox filed the Amended

Consolidated Class Action Complaint (the "Complaint"), alleging violations of Sections 11, 12

and 15 of the Securities Act of 1933 (the "Securities Act") against Defendants 2 for, inter alia,

failure to disclose in the Company's Registration Statement/Prospectus, issued in connection

with the IPO, that Sourcefire's customer orders were weak and that, in particular, customer

orders from the federal government had significantly declined. On November 20, 2007,

Defendants filed motions to dismiss the Complaint. The parties fully briefed Defendants'

motions to dismiss. On April 23, 2008, the Court denied in part and granted in part the motions

to dismiss holding that Lead Plaintiff's allegation that Defendants omitted material information

2 "Defendants" refers to Sourcefire, Inc. ("Sourcefire" or the "Company"), E. Wayne Jackson, III ("Jackson"),Thomas M. McDonough ("McDonough"), Todd P. Headley ("Headley"), Martin F. Roesch ("Roesch"), AsheemChandna ("Chandna"), Tim A. Guleri ("Guleri"), Harry R. Weller ("Weller"), Steven R. Polk ("Polk"), Arnold L.Punaro ("Punaro"), Joseph R. Chinnici ("Chinnici"), Morgan Stanley & Co. Incorporated ("Morgan Stanley"),Lehman Brothers Inc. ("Lehman"), UBS Securities LLC ("UBS"), Jefferies & Company, Inc. ("Jefferies") andSierra Ventures VII, LP ("Sierra Ventures").

Defendants Jackson, McDonough, Headley, Roesch, Chandna, Guleri, Weller, Polk, Punaro and Chinnici arehereinafter referred to as the "Individual Defendants." Morgan Stanley, Lehman, UBS and Jefferies are hereinafterreferred to as the "Underwriter Defendants."

2

in the Registration Statement/Prospectus regarding Sourcefire's customers and sales was

actionable. Defendants filed an Answer to the Complaint on May 7, 2008.

On June 18, 2008, Lead Plaintiff filed a motion to certify a class and appoint Lead

Plaintiff as Class Representative and Lead Counsel as counsel to the Class. The parties

exchanged discovery requests in May and June 2008, and on July 16, 2008, the parties stipulated

to, and the Court ordered, a stay of this action in order to pursue mediation. The parties' efforts

to resolve this Action are discussed below in Section II.C.

B. Discovery and Investigation

After about a year and a half of litigating and investigating this Action, Lead Plaintiff and

Lead Counsel have developed an in-depth understanding of the strengths and weaknesses of the

claims, as well as the viability of the defenses put forward by the Defendants. At the time the

Settlement Agreement was signed, the parties had already engaged in discovery.

Lead Counsel has reviewed and analyzed approximately 1,500 pages of documents and a

roadshow video presentation produced by Sourcefire, in addition to approximately 25,000 pages

of documents produced by third parties. Additionally, Lead Counsel deposed two Sourcefire

officers with knowledge regarding the allegations in the Complaint and served subpoenas on

twelve third parties, including customers and certain third parties who worked with Sourcefire in

preparation of the IPO.

C. The Settlement Negotiations

The parties, by and through their respective counsel, retained the Honorable Daniel

Weinstein (Ret.), who has been involved in the mediation and settlement of numerous securities

class actions, to serve as their mediator. Prior to the mediation session on October 17, 2008, the

parties drafted detailed mediation statements for submission to Judge Weinstein and at the

3

October 17 mediation session, the parties made presentations. The parties did not resolve the

Action at the mediation session. However, the parties continued to engage in settlement

discussions after the formal mediation session ended. Following almost three months of arms-

length negotiations, Lead Plaintiff and the Defendants have agreed to a Settlement of the Action,

as set forth in the Stipulation.

III. THE SETTLEMENT MEETS THE CRITERIA NECESSARY FOR THISCOURT TO GRANT PRELIMINARY APPROVAL

A. Factors to be Considered by the Court in the PreliminaryApproval of a Class Action Settlement

Federal Rule of Civil Procedure 23(e) requires judicial approval for any compromise of

claims brought on a class basis. Whether a proposed settlement should be granted approval is a

matter within the sound discretion of the district court, which should exercise such discretion in

the context of public policy strongly favoring the pretrial settlement of class action lawsuits. In

re Microstrategy, Inc. Sec. Litig., 148 F. Supp. 2d 654, 663 (E.D. Va. 2001); South Carolina

Nat? Bank v. Stone, 749 F. Supp. 1419, 1423 (D.S.C. 1990). As stated by the Court in

Microstrategy, "there is a strong initial presumption that the compromise is fair and reasonable."

148 F. Supp. 2d at 663 (quoting South Carolina Nat'l Bank v. Stone, 139 F.R.D. 335, 339

(D.S.C. 1991)).

Courts in the Fourth Circuit generally follow a two-step process in reviewing class action

settlements for approval. See Clark v. Experian Information Solutions, Inc., No. 00-1217-22,

2004 WL 256433, at *5 (D.S.C. Jan. 14,2004); In re Mid-Atlantic Toyota Antitrust Litig., 564 F.

Supp. 1379, 1384 (D. Md. 1983). The first step, the preliminary approval of a proposed

settlement, requires the court to "determine whether the proposed settlement is 'within the range

of possible approval,' or in other words, whether there is 'probable cause' to notify the class of

the proposed settlement." Horton v. Merrill Lynch, Pierce, Fenner & Smith, Inc., 855 F. Supp.

4

825, 827 (E.D.N.C. 1994); see also Mid-Atlantic Toyota, 564 F. Supp. at 1381("The principal

legal effect of [an order granting preliminary approval] is to allow notice to issue to potential

beneficiaries of the Settlement"); MANUAL FOR COMPLEX LITIGATION (THIRD) § 30.41 at 237

(1995) ("If the preliminary evaluation of the proposed settlement does not disclose grounds to

doubt its fairness or other obvious deficiencies. . . and appears to fall within the range of

possible approval, the court should direct that notice under Rule 23(e) be given. . ."). The

second step, following preliminary approval by the court and notice to the class, is a fairness

hearing where "all interested parties are afforded an opportunity to be heard on the proposed

settlement. The ultimate purpose of the fairness hearing is to determine if the proposed

settlement is 'fair, reasonable, and adequate.' Horton, 855 F. Supp at 827 (citation omitted).

B. The Proposed Settlement is Fair and Warrants the Court'sPreliminary Approval

Some courts have formalized the preliminary review by considering whether the

proposed settlement meets two factors: fairness and adequacy. See, e.g., Mid-Atlantic Toyota,

564 F. Supp. at 1383-84. Courts in the Fourth Circuit analyze four factors when assessing the

fairness of a proposed settlement: "(1) the posture of the case at the time settlement was

proposed, (2) the extent of discovery that had been conducted, (3) the circumstances surrounding

the negotiations, and (4) the experience of counsel in the area of securities class action

litigation." In re Jiffi) Lube Sec. Litig., 927 F.2d 155 (4th Cir. 1991) (citing In re Montgomery

County Real Estate Antitrust Litig., 83 F.R.D. 305, 315 (D. Md. 1979)). For preliminary

approval, the Court need only consider whether there is "probable cause" to find that these

factors support the proposed settlement. Mid-Atlantic Toyota, 564 F. Supp. at 1384.

5

1. The Posture of the Case and Extent of Discovery

As described above, at the time the parties reached the proposed Settlement, this Action

had been actively litigated for about a year and a half. By the time the settlement was reached,

Lead Plaintiff had opposed two motions to dismiss, consulted with a damages consultant, served

twelve subpoenas on various third parties, reviewed and analyzed over 26,000 pages of

documents produced by Defendants and third parties, participated in a mediation during which

the strengths and weaknesses of the case were discussed, deposed two of Sourcefire's officers,

and moved for class certification. This discovery, motion practice and consultation gave Lead

Plaintiff and Lead Counsel an understanding of the strengths and weaknesses of the claims of the

Class, as well as the risks they would face in obtaining a favorable jury verdict. Thus, Lead

Plaintiff respectfully submits that an analysis of the posture of the case as well as the extent of

discovery supports the Court's preliminary approval of the Settlement.

2. The Circumstances Surrounding the Negotiations andthe Experience of Counsel

The parties engaged in arms-length settlement negotiations for almost three months

before they reached the Settlement. These negotiations began with a mediation session before

Judge Weinstein on October 17, 2008, and continued thereafter. The parties' settlement

negotiations were hard fought and included discussion of the contested issues, including liability

and damages. There is no doubt that the Settlement was obtained without collusion, after good-

faith bargaining between the parties.

In addition, counsel for both Lead Plaintiff and Defendants have extensive experience in

litigating securities and other class actions, and have successfully litigated these types of actions

• in courts throughout the United States. Further, both Lead Counsel and Defendants' Counsel

have concluded that the proposed Settlement is fair and was reached in good faith. See Flinn v.

6

FMC Corp., 528 F.2d 1169, 1173 (4th Cir. 1975) ("While the opinion and recommendation of

experienced counsel is not to be blindly followed by the trial court, such opinion should be given

weight in evaluating the proposed settlement."). Therefore, Lead Plaintiff respectfully submits

that an analysis of these factors — the circumstances surrounding the negotiations and experience

of counsel — weighs in favor of preliminary approval.

C. The Settlement is Adequate and Warrants the Court'sPreliminary Approval

In assessing the adequacy of a proposed settlement, courts in the Fourth Circuit consider

the following factors:

(1) the relative strength of the plaintiffs' case on the merits, (2) the existence ofany difficulties of proof or strong defenses the plaintiffs are likely to encounter ifthe case goes to trial, (3) the anticipated duration and expense of additionallitigation, (4) the solvency of the defendants and the likelihood of recovery on alitigated judgment, and (5) the degree of opposition to the settlement.3

JO) Lube, 927 F.2d at 159 (citing Montgomery County Real Estate, 83 F.R.D. at 315-316).

Balanced against the strengths and weaknesses described below and the costs of continued

litigation, the proposed Settlement is more than adequate and should be preliminarily approved

by the Court.

1. The Strength of Plaintiff's Case and the PotentialDifficulties of Proof or Strong Defenses

Lead Plaintiff believes she has a fairly strong case against Defendants. Under Sections

11 and 12 of the Securities Act, plaintiff need only show that a registration statement/prospectus

contained an untrue statement of material fact or failed to disclose a material fact. See In re

Royal Ahold N.V. Sec. & ERISA Litig., 351 F. Supp. 2d 334, 399-402 (D. Md. 2004). There is no

reliance or scienter element; Lead Plaintiff is only required to prove negligence. Id. For the

3 The fifth factor, "the degree of opposition to the settlement," will be addressed in Lead Plaintiffs submission insupport of final approval, after notice has been disseminated and the Class has had the opportunity to consider theterms of the Settlement.

7

issuer, there is strict liability under Section 11. See 15 U.S.C. § 77k. Once plaintiff shows (i)

that the registration statement included a materially false statement or omission and (ii) statutory

damages, plaintiff prevails.4 Lead Plaintiff has also alleged a Section 15 claim under the

Securities Act. Section 15 provides for joint and several liability on the part of one who controls

a violator of Section 11 or 12. See 15 U.S.C. § 77o. At the time of the IPO, each of the

Individual Defendants was a director and/or senior officer of Sourcefire. Accordingly, once

Lead Plaintiff shows that Sourcefire violated Section 11 or 12, the Individual Defendants would

be jointly liable.

While Lead Counsel believes that Lead Plaintiff's claims have merit, litigation is never

free from risk and uncertainty and Lead Counsel recognizes that Lead Plaintiff's success is not

assured. See South Carolina Nat 'I Bank, 139 F.R.D. at 340 ("Although the plaintiffs. . . may

firmly believe that their claims have merit, the complexities and uncertainties characteristic of

class action securities litigation, and the associated expenses of such litigation, make it

appropriate for such plaintiffs to compromise their claims pursuant to a reasonable settlement.").

Thus, Lead Plaintiff is appropriately seeking approval of this Settlement.

Lead Plaintiff realizes she faces considerable risks and defenses. Defendants have

vigorously and consistently denied, and continue to deny, every allegation against them in the

Complaint. Moreover, defendants assert that they did not make statements in the Prospectus for

the IPO concerning the Company's first quarter 2007 results. Defendants also assert that any

statements made or facts allegedly omitted are not actionable under the securities laws. Further,

they assert that the price of Sourcefire common stock was not artificially inflated by reasons of

alleged misrepresentations, non-disclosures or otherwise, and that neither Lead Plaintiff nor the

4 The Underwriter Defendants, Individual Defendants and Sierra Ventures have a due diligence defense underSection 11, see 15 U.S.C. § 77k, and the Defendants named under Section 12, including Sourcefire, have a duediligence defense to that claim, see 15 U.S.C. § 771.

8

Class were harmed by the conduct alleged in the Action. Additionally, the Individual

Defendants and the Underwriter Defendants are likely to assert due diligence defenses. Thus,

Lead Plaintiff faces substantial risks at the summary judgment stage and at trial if the litigation

were to proceed. Therefore, Lead Plaintiff respectfully submits that an analysis of the strength of

Lead Plaintiffs case and the potential difficulties of proof or strong defenses warrants the

preliminary approval of the Settlement.

2. The Anticipated Duration and Expense of Additional Litigation

There is no question that the completion of merits discovery followed by expert

discovery, dispositive motions, a trial and the inevitable post-trial appeals would entail

substantial time and significant expense, possibly in the millions of dollars, for both sides.

Further litigation of this Action would also require many hours of the Court's time and resources.

Moreover, continued litigation through trial and the inevitable appeals would mean that recovery

for the Class would be delayed for years. Thus, an analysis of these factors supports a finding

that the Settlement falls within the range of reasonableness.

3. The Solvency of Defendants and Likelihood of Recoveryon a Litigated Judgment

Sourcefire's solvency or the Class's likelihood of recovering on a judgment rendered

against the Defendants is not contested. However, this should not preclude preliminary approval

of the Settlement. See Henley v. FMC Corp., 207 F. Supp. 2d 489, 494 (S.D.W.V. 2002) ("That

consideration [of this factor], however, is largely beside the point given the other factors

weighing in favor of a negotiated resolution."). Accordingly, Lead Plaintiff respectfully submits

that an analysis of all of the above factors weighs in favor of preliminary approval of the

Settlement.

9

IV. THE PROPOSED FORM AND METHOD OF CLASS NOTICEIS APPROPRIATE

Rule 23 requires that notice of a settlement be "the best notice that is practicable under

the circumstances, including individual notice to all members who can be identified through

reasonable effort." Fed. R. Civ. P. 23(c)(2)(B). In addition, the PSLRA imposes its own

requirements for notice. In order to comply with the PSLRA, the notice must state: (i) the

amount of the settlement proposed to be distributed to the parties in the action, determined in the

aggregate and on an average per-share basis; (ii) if the parties do not agree on the average

amount of damages per share that would be recoverable in the event plaintiff prevailed, a

statement from each settling party concerning the issue(s) on which the parties disagree; (iii) a

statement indicating which parties or counsel intend to make an application for an award of

attorneys' fees and costs (including the amount of such fees and costs determined on an average

per share basis), and a brief explanation supporting the fees and costs sought; (iv) the name,

telephone number, and address of one or more representatives of counsel for the plaintiff class

who will be reasonably available to answer questions concerning any matter contained in the

notice of settlement published or otherwise disseminated to the class; (v) a brief statement

explaining the reasons why the parties are proposing the settlement; and (vi) such other

information as may be required by the Court. See 15 U.S.C. § 78u-4(a)(7)(A)-(F).

As detailed in the proposed Order Preliminarily Approving Settlement and Providing for

Notice (the "Preliminary Order"), Lead Counsel and the Claims Administrator propose to mail

copies of the Settlement Notice and the Proof of Claim and Release form ("Proof of Claim") by

first class mail to all persons and entities who can be identified with reasonable effort by Lead

Counsel, including without limitation those persons and entities and entities on a list provided by

Sourcefire's transfer agent. In addition, Lead Counsel intends to publish a summary notice in the

10

national edition of the Wall Street Journal and on the Internet at

www.sourcefiresecuritieslitigation.com . Lead Counsel also intends to mail copies of the

Settlement Notice to nominee owners such as brokerage firms and other persons or entities who

purchased Sourcefire common stock during the Class Period, requesting that the Settlement

Notice be sent to all persons and entities for whom they act as nominee purchasers.

The proposed notice program fulfills the requirements of due process because the

proposed Settlement Notice alerts and informs those members of the Class who can be identified

through reasonable efforts of all of the information set forth above. In addition, the summary

notice to be published in the Wall Street Journal and on the Internet at

wwvv.sourcefiresecuritieslitigation.com provides an abbreviated description of the proposed

Settlement, and also explains how to obtain the more detailed Settlement Notice. Courts

routinely find that comparable notice programs meet the requirements of due process and Rule

23. See, e.g., Henley, 207 F. Supp. 2d at 494-95.

V. CONCLUSION

Based on the foregoing, Lead Plaintiff respectfully requests that the Court enter the

proposed Preliminary Order, which will: (i) give preliminary approval of the Settlement; (ii)

approve the form and manner of giving notice of the Settlement to the Class; (iii) provide a

schedule for the dissemination of the Settlement Notice and other proceedings required for the

Court's consideration of the Settlement; and (iv) schedule a Final Approval Settlement Hearing.

11

Dated: February 11, 2009 Respectfully Submitted,

TYD1NG • SENBERG LLP

/By: 7 if Jo sbis , ederal Bar No. 00639Jaim- vy . use, Federal Bar No. 27394100 East Pratt Street, 26' FloorBaltimore, MD 21202Telephone: (410) 752-9714Facsimile: (410) 727-5460

Liaison Counsel for Lead Plaintiff andthe Proposed Class

KAPLAN FOX & KILSHEIMER LLPRobert N. KaplanFrederic S. FoxHae Sung NamAviah Cohen Pierson850 Third Avenue, 14th FloorNew York, NY 10022

• Telephone: (212) 687-1980Facsimile: (212) 687-7114

Lead Counsel for Lead Plaintiff and the Proposed Class

12

EXHIBIT 1

UNITED STATES DISTRICT COURTDISTRICT OF MARYLAND

(Northern Division)

IN RE SOURCEFIRE, INC. : Master File No. 07-cv-01210-JFMSECURITIES LITIGATION •

STIPULATION AND AGREEMENT OF SETTLEMENT

This Stipulation of Settlement dated as of February 10, 2009 (the "Settlement Stipulation")

is submitted pursuant to Rule 23 of the Federal Rules of Civil Procedure. Subject to the approval

of the United States District Court for the District of Maryland (the "District Court"), this

Settlement Stipulation is entered into by Kaplan Fox & Kilsheimer LLP ("Kaplan Fox" or "Lead

Counsel") on behalf of Lead Plaintiff Sandra Amrhein ("Lead Plaintiff") and the other members of

the Class (as defined herein), and Defendants Sourcefire, Inc. ("Sourcefire" or the "Company"), E.

Wayne Jackson, III ("Jackson"), Thomas M. McDonough ("McDonough"), Todd P. Headley

("Headley"), Martin F. Roesch ("Roesch"), Asheem Chandna ("Chandna"), Tim A. Guleri

("Guleri"), Harry R. Weller ("Weller"), Steven R. Polk ("Polk"), Arnold L. Punaro ("Punaro"),

Joseph R. Chinnici ("Chinnici"), Morgan Stanley & Co. Incorporated ("Morgan Stanley"),

Lehman Brothers Inc. ("Lehman"), UBS Securities LLC ("UBS"), Jefferies & Company, Inc.

("Jefferies") and Sierra Ventures VII, LP ("Sierra Ventures"), by and through their undersigned

attorneys.

This Settlement Stipulation is intended by the parties to fully and finally compromise,

resolve, discharge and settle the Released Claims (as defined herein), subject to the terms and

conditions set forth below and final approval by the District Court.

1

RECITALS

The Litigation

A. WHEREAS, beginning May 8, 2007, a number of Sourcefire investors filed the

following putative securities class actions against Sourcefire, Inc., certain of its executives, one of

its investors and the underwriters of Sourcefire's March 9, 2007 initial public offering ("IPO"):

Case Civil No.1. Howard Katz v. Sourcefire, Inc., et al. 07-CV-012102. Mark Reaves v. Sourcefire, Inc., et al. 07-CV-013513. Joan Raveill v. Sourcefire, Inc., et al. 07-CV-014254. Barry Pincus v. Sourcefire, Inc., et al. 07-CV-02048

B. WHEREAS, on July 13, 2007, Sandra Amrhein and other Sourcefire investors

moved pursuant to the Private Securities Litigation Reform Act of 1995 ("PSLRA") to: 1)

consolidate the cases; 2) appoint Lead Plaintiff; and 3) appoint lead counsel. By an Order dated

September 4, 2007, the District Court consolidated the above-captioned cases • for all purposes

under the caption In re Sourcefire, Inc. Securities Litigation, Case No. 07-CV-01210 (the

"Action"), appointed Sandra Amrhein as Lead Plaintiff and appointed the law firm of Kaplan Fox

as Lead Counsel.

C. WHEREAS, on October 4, 2007, Lead Plaintiff filed an Amended Consolidated

Class Action Complaint (the "Complaint") alleging violations of Sections 11, 12 and 15 of the

Securities Act of 1933 (the "Securities Act"). The Action was brought on behalf of a purported

class of all persons or entities who purchased, through April 9, 2007, the common stock of

Sourcefire pursuant and/or traceable to the Company's registration statement and prospectus

issued in connection with Sourcefire's March 9, 2007 IPO.

D. WHEREAS, on November 20, 2007, each Defendant moved pursuant to Rule

12(b)(6) of the Federal Rules of Civil Procedure and the PSLRA to dismiss the Action. On April

2

23, 2008, the Court denied in part and granted in part Defendants' motions to dismiss. On June 18,

2008, Lead Plaintiff moved the Court to certify a class and appoint Lead Plaintiff as Class

Representative and Lead Counsel as counsel to the Class.

Discovery

E. WHEREAS, Lead Counsel has investigated the allegations of wrongdoing asserted

and the alleged damages suffered by the Class by way of informal and formal discovery.

F. WHEREAS, Lead Counsel has conducted discovery by reviewing approximately

1,500 pages of documents and a roadshow video presentation produced by Sourcefire and

deposing two Sourcefire officers with knowledge regarding the allegations in the Complaint.

G. WHEREAS, Lead Counsel served subpoenas on various non-parties, who worked

with Sourcefire in preparation of the IPO, including Ernst & Young LLP ("E&Y") and Latham and

Watkins LLP. Lead Counsel also served subpoenas on Stifel Financial Corporation ("Stifel") and

RBC Capital Markets ("RBC"). In addition, Lead Counsel served subpoenas on non-party

customers of Sourcefire, including ImmixGroup, Inc. ("immixGroup"), Verisign, Inc.

("Verisign"), Verizon Communications ("Verizon"), Lockheed Martin ("Lockheed"), Citigroup,

Inc. ("Citigroup"), Northrup Grumman ("Northrup"), Nokia Corporation ("Nokia"), and

Symantec Corporation ("Symantec"). A number of the non-parties, including E&Y, Stifel, RBC,

Verisign, Verizon, Lockheed, Citigroup, Northrup, Symantec and Nokia, produced documents

totaling approximately 25,000 pages which Lead Counsel reviewed and analyzed.

Settlement Negotiations

H. WHEREAS, the parties attended a mediation before Hon. Daniel Weinstein (Ret.).

The mediation, held in New York City on October 17, 2008, did not immediately result in

settlement of the Action. However, the parties continued to engage in settlement discussions after

3

the formal mediation session ended. Following arms-length negotiations for a lengthy period of

time, Lead Plaintiff and the Defendants have agreed to a settlement (the "Settlement") of the

Action, as set forth herein.

Defendants' Denials of Wrongdoing and Liability

I. WHEREAS, Defendants have denied, and continue to deny, each and every claim

and contention alleged in the Action. Defendants have expressly denied, and continue to deny, all

charges of wrongdoing or liability against them arising out of any of the conduct, statements, acts

or omissions alleged, or that could have been alleged, in the Action. Defendants have also denied,

and continue to deny, inter alia, the allegations that Lead Plaintiff or the Class have suffered

damage, that the price of Sourcefire common stock was artificially inflated by reasons of alleged

misrepresentations, non-disclosures or otherwise, or that Lead Plaintiff or the Class were harmed

by the conduct alleged in the Action.

J. WHEREAS, Defendants have concluded that further litigation would be protracted

and expensive, and that it is desirable to settle the Action, fully and finally, in the manner and upon

the terms and conditions set forth in this Settlement Stipulation. Defendants have also taken into

account the uncertainty and risks inherent in any litigation, especially in complex cases like this

Action. Defendants have determined that it is desirable and beneficial to them that the Action be

settled in the manner and upon the terms and conditions set forth in this Settlement Stipulation.

Benefits of the Settlement to the Class

K. WHEREAS, Lead Plaintiff and Lead Counsel believe that the Settlement provides

an excellent monetary recovery for the Class (as defined below) based on the claims asserted, the

evidence developed and the damages that might be proven by the Class in the Action.

4

L. WHEREAS, Lead Counsel, on behalf of Lead Plaintiff, recognizes the expense,

risks and uncertain outcome of any litigation and subsequent appeals, especially for a complex

action such as this with its inherent difficulties and delays. Lead Counsel is also mindful of the

inherent problems of proof and possible defenses to the Action, including being certified as a class

action, and therefore believes that it is desirable that the Released Claims (as defined below) be

fully and finally compromised, settled and resolved as set forth herein. Based upon their

evaluation, Lead Counsel, on behalf of Lead Plaintiff, has determined that the Settlement set forth

in this Settlement Stipulation is fair, reasonable, adequate and in the best interests of Lead Plaintiff

and the Class. Lead Plaintiff, on behalf of herself and all other members of the Class (collectively,

"Plaintiffs"), desires to settle the claims against the Defendants in this Action on the terms and

conditions set forth in this Settlement Stipulation. Further, Lead Plaintiff deems said Settlement to

be fair, reasonable, adequate and in the best interests of the members of the Class.

NOW, THEREFORE, without any admission or concession on the part of Lead Plaintiff or

Lead Counsel of any lack of merit of the Action, and without any admission or concession of any

liability or wrongdoing or lack of merit in the defenses whatsoever by Defendants, it is hereby

STIPULATED AND AGREED, by and among the parties to this Settlement Stipulation, through

their respective attorneys, subject to approval of the District Court pursuant to Rule 23(e) of the

Federal Rules of Civil Procedure, the PSLRA and other conditions set forth herein, in

consideration of the benefits flowing to the parties hereto from the Settlement, that the Action and

all Released Claims (as defined below) as against the Released Persons (as defined below) shall be

finally and fully compromised, settled, released and dismissed, on the merits and with prejudice, in

the manner and upon and subject to the terms and conditions hereafter set forth:

5

CERTAIN DEFINITIONS

1. The following capitalized terms used in this Settlement Stipulation shall have the

meanings specified below:

(a) The "Action" means the consolidated securities actions included in In re

Sourcefire, Inc. Securities Litigation, Case No. 07-CV-01210, in the United States District Court

for the District of Maryland.

(b) "Approval Order Entry Date" shall mean the date on which the District

Court enters the Order and Final Judgment approving the Settlement.

(c) "Authorized Claimant" means any Class Member whose claim for

recovery has been allowed pursuant to the terms of this Settlement Stipulation.

(d) "Claim" means the submission to be made by Class Members, on the

Proof of Claim form attached hereto as Exhibit A-2, or as may be required by the District Court.

(e) "Claims Administrator" means Complete Claims Solutions, LLC the firm

which Lead Counsel requests be appointed by the District Court to administer the Settlement and

disseminate notice to the Class.

(f) "Class" means the class that is certified by the District Court for purposes

of settlement of the Action. Included in such Class are all persons who purchased the publicly

traded common stock of Sourcefire during the period from March 9, 2007 through April 5, 2007,

inclusive. Excluded from the Class are any Released Persons.

(g) "Class Members" means Persons (defined below) who are members of the

Class who do not timely and properly exclude themselves therefrom.

(h) "Class Period" means March 9, 2007 through April 5, 2007, inclusive.

6

(i) "Defendants" are Sourcefire, Jackson, McDonough, Headley, Roesch,

Chandna, Guleri, Weller, Polk, Punaro, Chinnici, Morgan Stanley, Lehman, UBS, Jefferies, and

Sierra Ventures.

(j) "Defendants' Counsel" means the law firms of: (i) Hogan & Hartson LLP,

111 South Calvert Street, Suite 1600, Baltimore, MD, 21202, Tel: (410) 659-2700; (ii) Cooley

Godward Kronish LLP, One Freedom Square, Reston Town Center, 11951 Freedom Drive,

Reston, VA, 20190-5656, Tel: (703) 456-8000; and (iii) DLA Piper LLP (US), 500 Eighth Street,

NW, Washington, DC, 20004, Tel: (202) 799-4000.

(k) "Effective Date" means the first day following the date on which the

Settlement contemplated by this Settlement Stipulation shall become effective as set forth in 1125

below.

(1) "Escrow Account" means the interest-bearing account established

pursuant to 114-5 herein.

(m) "Escrow Agent" shall mean Kaplan Fox & Kilsheimer LLP. The Escrow

Agent shall perform the duties set forth in this Settlement Stipulation.

(n) "Final Approval" shall be calculated from the date of the entry of the

Order and Final Judgment (defined below) by the District Court in the Action: (i) approving the

Settlement; (ii) approving the release of the Released Claims as to the Released Persons as fair,

adequate and reasonable; and (iii) dismissing with prejudice the claims of the Lead Plaintiff and

the Class against the Defendants. "Final Approval" shall be deemed to occur upon the expiration

of any time for appeal or review of the Order and Final Judgment, or, if any appeal is filed and not

dismissed, after the Order and Final Judgment is upheld on appeal in all material respects and is

no longer subject to review upon appeal or review by certiorari or otherwise, and the time for any

7

petition for reargument, appeal or review, by certiorari or otherwise, has expired. In the event

that the District Court enters an order and final judgment in a form other than that provided above

("Alternative Judgment") and none of the parties hereto elect to terminate this Settlement, "Final

Approval" shall mean the date that such Alternative Judgment becomes final and no longer

subject to appeal or review by certiorari or otherwise, and the time for any petition for

reargument, appeal or review, by certiorari or otherwise, has expired.

(o) "Lead Counsel" means Kaplan Fox, selected by Lead Plaintiff and

appointed by the District Court to represent the interests of Lead Plaintiff and the Class.

(p) "Lead Plaintiff" means Sandra Amrhein, appointed by court order as Lead

Plaintiff.

(q) "Net Settlement Fund" shall have the meaning set forth in IT 5 herein.

(r) "Order and Final Judgment" means the order(s) and final judgment(s) to

be entered in the Action pursuant to II 24 of this Settlement Stipulation and substantially in the

form of Exhibit B hereto.

(s) "Person" and "Persons" means any individual, corporation, partnership,

association, affiliate, joint stock company, estate, trust, unincorporated association, entity,

government and any political subdivision thereof, or any other type of business or legal entity,

and their spouses, heirs, predecessors, successors, representatives, agents, or assignees.

(t) "Plaintiffs' Counsel" means those firms that, at the direction of Lead

Counsel, performed work in this Action.

(u) "Plan of Distribution" means the plan for distributing the Net Settlement

Fund (as set forth in the Notice of Pendency and Proposed Settlement of Class Action) to

Authorized Claimants after payment of expenses of notice and administration of the Settlement,

8

Taxes and Tax Expenses and such attorneys' fees, costs and expenses as may be awarded by the

District Court.

(v) "Preliminary Order" means the Preliminary Order in connection with

settlement proceedings that Lead Counsel and Defendants will seek from the District Court,

substantially in the form attached as Exhibit A and as described in '11 23 below.

(w) "Publication Notice" means the summary notice of pendency and

proposed settlement for publication substantially in the form attached as Exhibit A-3.

(x) "Released Claims" shall mean any and all claims, debts, demands, rights,

causes of action or liabilities of every nature and description whatsoever (including, but not

limited to, claims for damages, interest, attorneys' fees, expert or consulting fees, and any other

costs, expenses, or liability whatsoever), whether based in law or equity, whether fixed or

contingent, accrued or unaccrued, liquidated or unliquidated, matured or not matured, pursuant to

federal, state, local, statutory or common law, or any other law, rule or regulation, including both

known claims and Unknown Claims, that have been or could have been asserted in any forum by

the Class Members, or any of them, or the successors or assigns of any of them, against any of the

Released Persons, which arise out of, are based on, or relate in any way to, directly or indirectly,

any of the allegations, acts, transactions, facts, events, matters, occurrences, acts, representations

or omissions involved, set forth, alleged or referred to, in the Complaint, or which could have

been alleged based upon the facts alleged in the Complaint, and which arise out of, are based

upon or are related in any way, directly or indirectly, to the purchase or other acquisitions of any

Sourcefire common stock by any Class Member during the Class Period.

(y) "Released Persons" means each and all of the Defendants, personal or

legal representatives of the Defendants, related or affiliated entities of the Defendants (including

9

any Sierra Ventures related entity or partnership including but not limited to Sierra Ventures V,

L.P., Sierra Ventures VI, L.P., Sierra Ventures VII, L.P., Sierra Ventures VIII-A, L.P., Sierra

Ventures VIII-B, L.P., Sierra Ventures IX, L.P., SV Associates V, L.P., SV Associates VI, L.P.,

Sierra Ventures Associates VII, LLC, Sierra Ventures Associates VIII, LLC, Sierra Ventures

Associates IX, LLC, Sierra Ventures Finance Limited L.P., Sierra Ventures Mauritius, Sierra

Ventures Venture Member VIII, LLC, Sierra Ventures Venture Member IX, LLC, Sierra

Ventures Venture Member Management VIII, LLC, Sierra Ventures Venture Member

Management IX, LLC, Sierra Ventures Management, LLC, Sierra Ventures Management II,

LLC), any entity in which a Defendant has a controlling interest, affiliates, predecessors in

interest, successors in interest, assigns, employees, agents, representatives, attorneys, advisors,

accountants, auditors and insurers, co-insurers, re-insurers of the Defendants, the past and

present parents, subsidiaries, controlling shareholders, partners, members, principals, divisions,

joint ventures, officers and directors of any of the foregoing that is an entity, any spouses or

members of the immediate family of any of the foregoing persons who is a natural person, and

the estates, retirement plans, heirs, devisees and legatees of any of the foregoing persons who is a

natural person and any trust of which a Defendant is the settler of or which is for the benefit of a

Defendant's family.

(z) "Settlement" means the settlement as set forth in this Settlement

Stipulation.

(an) "Settlement Amount" means $3.2 million (Three Million Two Hundred

Thousand Dollars) in cash.

(bb) "Settlement Fund" means the payment made pursuant to 4 herein.

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(cc) "Settlement Notice" means the Notice of Pendency of Class Action and

Proposed Settlement which is to be sent to Class Members substantially in the form attached

hereto as Exhibit A-1.

(dd) "Tax Expenses" means any expenses and costs incurred in connection

with the payment of Taxes (including, without limitation, expenses of tax attorneys and/or

accountants and expenses relating to the filing of all necessary or advisable tax returns).

(ee) "Taxes" means any taxes due and payable with respect to the income

earned by the Settlement Fund, including any interest or penalties thereon.

(If) "Unknown Claims" means any and all Released Claims that Lead Plaintiff

or any Class Member does not know or suspect to exist in his, her or its favor at the time of the

release of the Released Persons. With respect to any and all Released Claims, the parties

stipulate and agree that upon the Effective Date, Lead Plaintiff shall expressly, and each Class

Member shall be deemed to have, and by operation of the Order and Final Judgment shall have,

expressly waived any and all provisions, rights and benefits conferred by any law of any state or

territory of the United States, or principle of common law, which is similar, comparable or

equivalent to Cal. Civ. Code § 1542, which provides:

A general release does not extend to claims which the creditor does notknow or suspect to exist in his or her favor at the time of executing the release,which if known by him or her must have materially affected his or her settlementwith the debtor.

Lead Plaintiff and Defendants acknowledge, and Class Members by operation of law shall be

deemed to have acknowledged, that the inclusion of "Unknown Claims" in the definition of

Released Claims was separately bargained for and was a key element of the Settlement.

Defendants, including any and all of their respective successors in interest, predecessors,

representatives, trustees, executors, administrators, heirs, assigns or transferees, immediate and

11

remote, and any person or entity acting for or on behalf of, or claiming under any of them, and each

of them, release Plaintiffs and Plaintiffs' counsel in the Action from any and all claims arising out

of or relating to their filing and prosecution of the action.

SCOPE AND EFFECT OF SETTLEMENT

2. The obligations incurred pursuant to this Settlement Stipulation shall be in full and

final disposition of the Action as against Defendants and any and all Released Claims as against all

Released Persons.

3. (a) Upon the Effective Date of this Settlement, Class Members, on behalf of

themselves, their heirs, joint tenants, tenants in common, beneficiaries, executors and

administrators, successors and assigns, release and shall be deemed to have released, dismissed

and forever discharged the Released Claims against each and all of the Released Persons, with

prejudice and on the merits, without costs to any party.

(b) Lead Plaintiff and all Class Members, whether or not any such person

submits a Proof of Claim, or otherwise shares in the Settlement Fund, on behalf of themselves and

each of their predecessors, successors, assigns, personal representatives, heirs and any other

person who purports to claim through them, will be deemed by this Settlement to release and

forever discharge the Released Persons from any and all of the Released Claims. As of the

Effective Date, Lead Plaintiff and all Class Members and anyone claiming through or on behalf of

any of them, are forever barred and enjoined from commencing, instituting, prosecuting or

continuing to prosecute against any of the Released Persons, and each of them, any of the Released

Claims.

(c) Upon the Effective Date of the Settlement, all claims for contribution,

indemnification, or any other form of relief by other alleged joint tortfeasors against any of the

12

Released Persons based upon, arising out of, relating to, or in connection with the Released Claims

of the Class or any Class Member are thereby barred, extinguished, discharged, satisfied and

otherwise rendered unenforceable to the full extent permitted by law, and the future filing of any

such claims enjoined. Nothing in this Settlement shall be deemed to release, impair or affect the

indemnity rights of any Released Persons.

THE SETTLEMENT CONSIDERATION

4. (a) In full and complete settlement of the Released Claims, Defendants have

agreed to pay or cause to be paid $3.2 million cash as follows. The amount of $100,000 (the

"Initial Payment") shall be paid into the Escrow Account established for the Settlement Fund by

Lead Counsel for the benefit of the Class Members within five (5) business days of the execution

of the Settlement Stipulation. The Defendants shall cause the remainder of the settlement amount,

amounting to $3.1 million (the "Second Payment"), to be paid into the Escrow Account

established for the Settlement Fund by Lead Counsel for the benefit of the Class Members within 3

business days of the Approval Order Entry Date.

(b) All amounts paid into the Escrow Account shall be invested in suitable

investment instruments within five (5) days of their receipt. Suitable investment instruments shall

mean short-term instruments backed-up by the full faith and credit of the United States

Government, or fully insured by the United States Government or an agency thereof, with a

maturity of less than ninety-one (91) days. The Escrow Account shall be maintained by Valley

National Bank and the Second Payment shall be invested in 30-day United States Treasury Bills in

accordance with the terms set forth herein in T4(b). Lead Counsel shall provide the parties with

statements reflecting activity in the Escrow Account on a quarterly basis until the Effective Date.

The rights and obligations of the Escrow Agent shall not be assigned or otherwise transferred to

someone other than an attorney of Lead Counsel unless at least thirty (30) days advance notice has

13

been provided to the persons identified in 144 and approval has been obtained from the District

Court.

5. Each of the Initial Payment and the Second Payment, net of any Taxes and Tax

Expenses, shall be used to pay: 1) reasonable out-of-pocket costs in connection with providing

notice of the Settlement to the Class ("Notice") and for other reasonable out-of-pocket

administrative expenses (the "Notice and Administration Fund"), 2) the attorneys' fee and expense

award referred to in ¶1110-12 hereof, and 3) the remaining administration expenses referred to in ¶11

8, 14 hereof. The balance of the Initial Payment and the Second Payment after the above payments

shall be the "Net Settlement Fund," which shall be distributed to the Authorized Claimants as

provided in II 13-22 hereof. All costs and expenses incurred by or on behalf of the Lead Plaintiff

and the Class associated with the Settlement shall be paid from the Initial Payment and the Second

Payment and in no event shall any of the Released Persons bear any further or additional

responsibility for any such costs or expenses beyond payment of the Initial Payment and the

Second Payment.

6. The amount of $100,000 paid as set forth in 4 above shall be allocated to the

Notice and Administration Fund. Upon written agreement of the parties, or order of the District

Court, additional amounts may be transferred from the Settlement Fund to the Notice and

Administration Fund. All funds held by the Escrow Agent shall be deemed to be in the custody of

the District Court and such funds shall remain subject to the jurisdiction of the District Court until

such time as the funds shall be distributed or returned to Defendants pursuant to this Stipulation

and/or further order of the District Court. The Escrow Agent shall hold the funds in an interest

bearing bank account insured by the FDIC and/or United States Agency or Treasury securities or

obligations.

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7. Upon the payment of the Settlement Fund or any portion thereof, the parties agree

to treat the Settlement Fund as a Qualified Settlement Fund within the meaning of Treasury

Regulation § 1.468B-1 and the Claims Administrator shall be responsible for timely making such

elections as are necessary or advisable to carry out the provisions of this paragraph, including but

not limited to the relation-back election (as defined in Treasury Reg. § 1.468B-1) to the earliest

permitted date. Such elections shall comply with the procedures and requirements contained in

such Regulations. Additionally, it shall be the responsibility of the Claims Administrator to

prepare and deliver the necessary documentation for signature by all necessary parties, and

thereafter to cause the appropriate filing(s) to occur. The Claims Administrator and Lead Counsel,

as required, shall do all things that are necessary or advisable to carry out the provisions of this

paragraph and Defendants shall reasonably cooperate with the Claims Administrator and Lead

Counsel to carry out the provisions of this paragraph.

8. All Taxes (including any interest) arising with respect to the income earned by the

Settlement Fund after the Settlement Amount is paid into a segregated account, including any

Taxes or Tax detriments that may be imposed upon Defendants with respect to any income earned

by the Settlement Fund for any period during which the Settlement Fund does not qualify as a

"qualified settlement fund" for Federal or state income tax purposes and all Tax Expenses shall be

considered to be a cost of administration of the Settlement and shall be paid out of the Settlement

Fund. The Released Persons shall not have any liability or responsibility for any such Taxes or

Tax Expenses. The Settlement Fund shall indemnify and hold each of the Released Persons

harmless for Taxes and Tax Expenses (including, without limitation, Taxes payable by reason of

any such indemnification). Lead Counsel, or their agents, shall timely and properly file all

informational and other tax returns necessary or advisable with respect to the Settlement Fund and

15

the distributions and payments therefrom, including, without limitation, the tax returns described

in Treas. Reg. § 1.468B-2(k), and to the extent applicable, Treas. Reg. § 1.468B-2(I). Such returns

shall be consistent with the terms hereof and in all events shall reflect that all such Taxes, including

any interest, on the income earned by the Settlement Fund shall be paid out of the Settlement Fund,

subject to the limitations set forth in this paragraph. Lead Counsel, or their agents, shall also

timely pay Taxes and Tax Expenses, subject to the limitations set forth in this paragraph, out of the

Settlement Fund, and are authorized to withdraw, without prior order of the District Court, from

the Settlement Fund amounts necessary to pay Taxes and Tax Expenses. The parties hereto agree

to cooperate with the Claims Administrator, each other, and their tax attorneys and accountants to

the extent reasonably necessary to carry out the provisions of this Stipulation. The Released

Persons shall have no responsibility or liability for the acts or omissions of Lead Counsel or their

agents, as described herein.

9. The finality of the Settlement shall not be conditioned on any ruling by the District

Court concerning the Plan of Distribution or the award of attorneys' fees and expenses. Any order

or proceeding relating to a request for approval of the Plan of Distribution, or any appeal from any

order relating thereto or reversal or modification thereof, shall not operate to terminate the

Settlement or affect or delay the Effective Date or the effectiveness or finality of the Order and

Final Judgment and the release of the Released Claims. There shall be no distribution of any of the

Settlement Fund to any Class Member until the Plan of Distribution is finally approved and such

order of approval is affirmed on appeal and/or is no longer subject to review by appeal or certiorari,

and the time for any petition for rehearing, appeal, or review, by certiorari or otherwise, has

expired.

16

ATTORNEYS' FEES AND EXPENSES

10. Lead Counsel will apply to the District Court for an award from the Settlement

Fund of attorneys' fees plus reimbursement of actual expenses. Such amounts as are awarded by

the District Court shall be payable from the Settlement Fund to Lead Counsel pursuant to 14.

Lead Counsel shall allocate the attorneys' fees and expense awards amongst Plaintiffs' counsel in

a manner in which they in good faith believe reflects the contributions of such counsel to the

prosecution and settlement of the action.

11. The Released Persons shall have no responsibility or liability for, and take no

position with respect to, the allocation of any award of fees or expenses that the District Court may

make in this action to Lead Counsel.

12. The procedure for and amounts of any award of attorneys' fees and expenses, and

the allowance or disallowance by the District Court thereof, shall not be a condition of the

Settlement. Lead Counsel shall request that their application for an award of attorneys' fees and

expenses be considered by the District Court separately from the District Court's consideration of

the fairness and adequacy of the Settlement. Any order or proceedings relating to such request, or

any appeal from any order relating thereto or reversal or modification thereof, shall not operate to

terminate the Settlement or affect or delay the Effective Date or the effectiveness or finality of the

Order and Final Judgment and the release of the Released Claims. The finality of the Settlement

shall not be conditioned on any ruling by the District Court concerning Lead Counsel's application

for attorneys' fees and expenses.

DISTRIBUTION TO AUTHORIZED CLAIMANTSAND ADMINISTRATION OF SETTLEMENT

13. Lead Counsel or the Claims Administrator, subject to the supervision, direction and

approval of the District Court, shall administer and calculate the Claims submitted by Class

17

Members, oversee distribution of the Settlement Fund and perform all claims administration

procedures necessary or appropriate in connection therewith. The Released Persons shall have no

liability, obligation or responsibility for the Class notice, administration or processing of claims or

disbursement of the Net Settlement Fund, including without limitation, determinations as to the

validity of any Proof of Claim, the amounts of claims, distributions of the Settlement Fund, or any

loss incurred by the Escrow Agent or the Claims Administrator and Defendants shall take no

position in regard to such matters. Defendants shall cooperate in the administration of the

Settlement only to the extent reasonably necessary to effectuate its terms as requested by Lead

Counsel.

14. The Settlement Amount and Fund shall be applied as follows:

(a) To pay all costs and expenses incurred in connection with providing

notice to the Class, locating members of the Class, soliciting claims, assisting with the filing of

claims, administering and distributing the Settlement Fund to the Class Members, processing

proofs of claim, processing requests for exclusion and costs;

(b) To pay Taxes and Tax Expenses owed by the Settlement Fund;

(c) Subject to the approval and further order(s) of the District Court, for

payment of all attorneys' fees and expense reimbursement as may be awarded by the District

Court to Lead Counsel, who may make payment therefrom to other Plaintiffs' Counsel as the

former deems appropriate based upon the work done by such other Plaintiffs' Counsel and such

other Plaintiffs' Counsel's relative contribution to the prosecution and settlement of the Actions;

(d) Subject to the approval and further order(s) of the District Court, and upon

the Effective Date, to distribute the Net Settlement Fund (as defined in I 5) to Authorized

Claimants as provided herein and in the manner set forth in the notice attached hereto as Exhibit

18

A-1 (which notice shall include a Plan of Distribution of the Net Settlement Fund), or as

otherwise ordered by the District Court in order to participate in such distribution of the Net

Settlement Fund.

15. For purposes of determining the extent, if any, to which a Class Member shall be

entitled to be treated as an "Authorized Claimant," the following conditions shall apply:

(a) Each Class Member seeking to participate in distributions from the Net

Settlement Fund shall be required to timely submit to the Claims Administrator a separate signed

Proof of Claim (in the form attached hereto as Exhibit A-2), supported by such documents as are

designated therein, including proof of all purchases and sales of the Sourcefire common stock

listed from the beginning of the Class Period to July 26, 2007, the Claimant's loss, or such other

documents or proof as Lead Counsel, in their discretion, may deem acceptable;

(b) All Proofs of Claim must be submitted by the date specified in the

Settlement Notice unless such period is extended by Order of the District Court. Any Class

Member who fails to submit a Proof of Claim within such period shall be forever barred from

receiving any payment pursuant to this Settlement Stipulation (unless, by Order of the District

Court, a later submitted Proof of Claim by such Class Member is approved), but in all other

respects shall be subject to and bound by the provisions of this Settlement Stipulation and the

Settlement including the terms of the Order and Final Judgment to be entered in the Action and the

releases of the Released Claims provided for herein, and will be barred from bringing any action or

proceeding against any of the Released Persons concerning the Released Claims. Provided that it

is received before the motion is made to distribute the Settlement proceeds to the Class, a Proof of

Claim shall be deemed to have been submitted when postmarked, if received with a postmark

indicated on the envelope and if mailed by first-class mail, postage prepaid, and addressed in

19

accordance with the instructions thereon. In all other cases, the Proof of Claim shall be deemed to

have been submitted when actually received by the Claims Administrator;

(c) Each Proof of Claim shall be submitted to and reviewed by the Claims

Administrator, under the supervision of Lead Counsel, who shall determine in accordance with

this Settlement Stipulation the extent, if any, to which each claim shall be allowed, subject to

review by the District Court pursuant to subparagraph (e) below;

(d) Proofs of Claim that do not meet the submission requirements may be

rejected. Prior to rejection of a Proof of Claim, the Claims Administrator shall communicate with

the claimant in order to afford the claimant opportunity to remedy any curable deficiencies in the

Proof of Claims submitted. The Claims Administrator shall notify, in a timely fashion and in

writing, all claimants whose Proofs of Claim it proposes to reject in whole or in part, setting forth

the reasons therefore, and shall indicate in such notice that the claimant whose claim is to be

rejected has the right to a review by the District Court if the claimant so desires and complies with

the requirements of subparagraph (e) below;

(e) If any claimant whose claim has been rejected in whole or in part desires to

contest the rejection, the claimant must, within twenty (20) days after the date of mailing of the

notice required in subparagraph (d) above, serve upon the Claims Administrator a notice and

statement of reasons indicating the claimant's grounds for contesting the rejection along with any

supporting documentation, and requesting a review thereof by the District Court. If a dispute

concerning a claim cannot be otherwise resolved, Lead Counsel shall present the request for

review to the District Court. If a claimant fails to serve upon the Claims Administrator the notice

required in this paragraph, his, her or its Proof of Claim, to the extent rejected, will not be allowed;

and

20

(f) The administrative determinations of the Claims Administrator accepting

and rejecting claims shall be presented to the District Court, on notice to Defendants' Counsel, for

approval by the District Court.

16. Each claimant shall be deemed to have submitted to the jurisdiction of the District

Court with respect to his, her or its claim, and the claim will be subject to investigation and

discovery under the Federal Rules of Civil Procedure, provided that such investigation and

discovery shall be limited to the claimant's status as a Class Member and the validity and amount

of the claimant's claim. No discovery shall be allowed on the merits of the Action or Settlement in

connection with processing of the Proofs of Claim.

17. No Class Member or Authorized Claimant shall have any claim against Lead

Counsel, Lead Plaintiff, any other Plaintiff and Plaintiffs' Counsel in the Action, any of the

Released Persons or their counsel, the Claims Administrator or any employees or agents of any of

the foregoing, based on the distributions made substantially in accordance with this Settlement

Stipulation or as otherwise approved or directed by the District Court. Payment pursuant to this

Settlement Stipulation shall be deemed final and conclusive against all Class Members. All Class

Members whose claims are not approved by the District Court shall be barred from participating in

distributions from the Net Settlement Fund, but otherwise shall be subject to and bound by the

provisions of this Settlement Stipulation and the Settlement, including the terms of the Order and

Final Judgment to be entered in the Action and the releases provided for herein, and will be barred

from bringing any action against any of the Released Persons concerning the Released Claims.

18. All proceedings with respect to the administration, processing and determination of

claims described by 1115 of this Settlement Stipulation and the determination of all controversies

21

relating thereto, including disputed questions of law and fact with respect to the validity of claims,

shall be subject to the jurisdiction of the District Court.

19. The Net Settlement Fund shall be distributed to Authorized Claimants by the

Claims Administrator only after the Effective Date and after: (i) all timely Proofs of Claim have

been processed and all claimants whose claims have been rejected or disallowed, in whole or in

part, have been notified and provided the opportunity to be heard concerning such rejection or

disallowance; (ii) all objections with respect to all rejected or disallowed claims have been

resolved by the District Court, and all appeals therefrom have been resolved or the time therefor

has expired; (iii) all matters with respect to attorneys' fees, costs and disbursements have been

resolved by the District Court, all appeals therefrom have been resolved or the time therefor has

expired; and (iv) all costs of administration have been paid.

20. In the interests of achieving substantial justice, Lead Counsel shall have the right,

but not the obligation, to advise the Claims Administrator to waive what they deem to be formal or

technical defects in any submitted Proofs of Claim.

21. Following distribution of the Net Settlement Fund, the Claims Administrator shall

• maintain the completed Proofs of Claim on file for three years after the Effective Date.

22. Each Member of the Class certified for purposes of settlement only shall be bound

by all determinations and judgments in the Action concerning the Settlement unless such person

shall mail, by first class mail, a written request for exclusion from the Class. In order to be valid, a

Request for Exclusion must state: (1) the name and address of the person requesting exclusion; (2)

the person's purchases and sales of Sourcefire common stock made from the beginning of the

Class Period to July 26, 2007, including the dates, the number of shares, and prices paid or

received per share for each such purchase or sale; and (3) that the person wishes to be excluded

22

from the Class. Such Person should also state his telephone number. All persons who submit valid

and timely Requests for Exclusion in the manner set forth in this paragraph shall have no rights

under this Stipulation, shall not share in the distribution of the Net Settlement Fund, and shall not

be bound by the Stipulation of Settlement or the Judgment.

TERMS OF PRELIMINARY ORDER INCONNECTION WITH SETTLEMENT PROCEEDINGS

23. Promptly after execution of this Settlement Stipulation, Lead Counsel and

Defendants' Counsel shall submit the Settlement Stipulation together with its Exhibits to the

District Court and shall jointly apply for entry of a Preliminary Order in Connection with

Settlement Proceedings substantially in the form annexed hereto as Exhibit A.

TERMS OF ORDER AND FINAL JUDGMENT

24. If the Settlement contemplated by this Settlement Stipulation is approved by the

District Court, Lead Counsel and Defendants' counsel shall jointly request that the District Court

enter an Order and Final Judgment substantially in the form annexed hereto as Exhibit B. The

Settlement is expressly conditioned upon, among other things, the entry of an Order and Final

Judgment substantially in the form annexed hereto as Exhibit B.

EFFECTIVE DATE OF SETTLEMENT, WAIVER OR TERMINATION

25. The Effective Date of Settlement shall be the latest date when all the following

shall have occurred:

(a) entry of the Preliminary Order;

(b) approval by the District Court of the Settlement and certification of the

Class following notice to the Class and a hearing in accordance with Rule 23 of the Federal Rules

of Civil Procedure;

(c) Final Approval (as defined above in paragraph 1(n); and

23

(d) dismissal with prejudice of the Action.

26. Defendants' Counsel or Lead Counsel shall have the right to terminate the

Settlement and this Settlement Stipulation by providing written notice of their election to do so

("Termination Notice") to the other within thirty (30) days of the date on which: 1) the District

Court declines to enter the Preliminary Order; 2) the District Court refuses to approve this

Settlement Stipulation or any material part of it; 3) the District Court declines to enter the Order

and Final Judgment; 4) the Order and Final Judgment is vacated, modified or reversed in any

material respect by the United States Court of Appeals for the Fourth Circuit or the United States

Supreme Court; 5) an Alternative Judgment is vacated, modified or reversed in any material

respect by the United States Court of Appeals for the Fourth Circuit or the United States Supreme

Court; or 6) the Effective Date of Settlement otherwise does not occur. The foregoing list is not

intended to limit or impair the parties' rights under the law of contracts of the State of Maryland

with respect to any breach of this Settlement Stipulation. In the event the Settlement and this

Settlement Stipulation are terminated, the provisions of IT 6-8, 27, 28, 32, 33 and 44 shall survive

termination.

27. In the event the Settlement and this Settlement Stipulation are terminated or if the

Effective Date fails to occur for any reason, the parties to this Settlement Stipulation shall be

deemed to have reverted nunc pro tunc to their respective status in the Action as of the date and

time immediately prior to the execution of this Settlement Stipulation and, except as otherwise

expressly provided, the parties shall proceed in all respects as if this Settlement Stipulation and any

related orders had not been entered and without any prejudice in any way from the negotiation, fact

or terms of this Settlement.

24

28. In the event this Settlement Stipulation is terminated or if the Effective Date fails to

occur for any reason, then within ten (10) business days after written notice is sent by Lead

Counsel or Defendants' Counsel, the balance of the Settlement Fund including the Notice and

Administration Fund, less any expenses paid or incurred but not yet paid, shall be refunded to

Sourcefire, including interest accrued thereon. In such event, the parties to this Settlement

Stipulation shall be deemed to have reverted nunc pro tunc to their respective status as of the date

and time immediately before the execution of this Settlement Stipulation and, except as otherwise

expressly provided, they shall proceed in all respects as if this Settlement Stipulation and related

orders had not been entered and without prejudice in any way from the negotiation, fact or terms of

this Settlement. In the event the Settlement and this Settlement Stipulation are terminated, the

provisions of[ 6-8, 27, 28, 32, 33 and 44 shall survive termination.

NO ADMISSION OF WRONGDOING

29. This Settlement Stipulation, whether or not consummated, and any proceedings

taken pursuant to it:

(a) shall not be offered or received against any Defendant, any other Released

Party, Lead Plaintiff or the Class as evidence of, or be deemed to be evidence of, any

presumption, concession or admission by any of the Defendants or any of the other Released

Persons or by any of the Lead Plaintiff or the Class with respect to the truth of any fact alleged by

Lead Plaintiff or the validity, or lack thereof, of any claim that had been or could have been

asserted in the Action or in any litigation, or the deficiency of any defense that has been or could

have been asserted in the Action or in any litigation, or of any liability, negligence, fault or

wrongdoing of Defendants or other Released Persons;

(b) shall not be offered or received against any of the Released Persons as

evidence of a presumption, concession or admission of any fault, misrepresentation or omission

25

with respect to any statement or written document approved or made by any Released Party, or

against Lead Plaintiff or the Class as evidence of any infirmity in the claims of Lead Plaintiff and

the Class;

(c) shall not be offered or received against any of the Released Persons, Lead

Plaintiff or the Class as evidence of a presumption, concession or admission with respect to any

liability, negligence, fault or wrongdoing, or in any way referred to for any other reason as

against any of the parties to this Settlement Stipulation, in any arbitration proceeding or other

civil, criminal or administrative action or proceeding, other than such proceedings as may be

necessary to effectuate the provisions of this Settlement Stipulation; provided, however, that if

this Settlement Stipulation is approved by the District Court, the Released Persons may refer to it

to effectuate the liability protection granted them hereunder;

(d) shall not be construed against any of the Released Persons, Lead Plaintiff

or the Class as an admission or concession that the consideration to be given hereunder represents

the amount which could be or would have been recovered after trial; and

(e) shall not be construed as or received in evidence as an admission,

concession or presumption against Lead Plaintiff or the Class or any of them that any of their

claims are without merit or that damages recoverable in the Action would not have exceeded the

Settlement Fund.

30. This Settlement Stipulation and the Settlement may be pleaded as a full and

complete defense to any action, suit or other proceeding that may be instituted, prosecuted or

attempted with respect to any of the Released Claims. The Released Persons may offer the

Settlement Stipulation or Order and Final Judgment from the Action in any other action that may

be brought against them by any Class Member or other Released Party in order to support a

26

defense or counterclaim based on principles of res judicata, collateral estoppel, release, good faith

settlement or any similar defense or counterclaim. The Class Members and Defendants agree that

any such proceeding would cause irreparable injury to the party against whom it is brought and

that the District Court or any court of competent jurisdiction may enter an injunction restraining

the prosecution of such proceeding.

NOTICE AND ADMINISTRATION FUND

31. The Notice and Administration Fund shall be used by Lead Counsel or the Escrow

Agent to pay the costs of notifying the Class, soliciting the filing of claims by Class Members,

assisting them in making their claims, and otherwise administering the Settlement on behalf of the

Class.

32. As of the Effective Date, any balance, including interest, then remaining in the

Notice and Administration Fund, less expenses incurred but not yet paid, shall be returned to the

Settlement Fund. Thereafter, Lead Counsel shall have the right to use such portions of the

Settlement Fund as are, in their exercise of reasonable judgment, necessary to carry out the

purposes set forth 14 above. Lead Counsel will establish an Escrow Account into which the

Notice and Administration Fund will be deposited.

33. If the Effective Date does not occur, the balance of the Notice and Administration

Fund that has not been expended, including all interest accrued thereon, shall be returned to

Sourcefire.

MISCELLANEOUS PROVISIONS

34. All of the Exhibits attached hereto are hereby incorporated by reference as though

fully set forth herein. Notwithstanding the foregoing, in the event that there exists a conflict or

inconsistency between the terms of this Settlement Stipulation and the terms of any exhibit hereto,

the terms of this Settlement Stipulation shall prevail.

27

35. This Settlement Stipulation may not be modified or amended, nor may any of its

provisions be waived except by a writing signed by all parties hereto or their

successors-in-interest.

36. Neither the Settlement Stipulation nor the Settlement, nor any act performed or

document executed pursuant to or in furtherance of the Settlement Stipulation or the Settlement: (i)

is or may be deemed to be or may be used as an admission or evidence of the validity of any

Released Claim or of any wrongdoing or liability of any of the Released Persons; or (ii) is or may

be deemed to be or may be used as an admission or evidence of any fault or omission of any of the

Released Persons in any civil, criminal or administrative proceeding in any court, any arbitration

proceeding or any administrative agency or other tribunal, other than in such proceedings as may

be necessary to consummate or enforce the Settlement Stipulation, the Settlement or the Order and

Final Judgment.

37. The parties to this Settlement Stipulation intend the Settlement to be a final and

complete resolution of all disputes asserted or which could be asserted by the Class Members

against any of the Released Persons with respect to the Released Claims. Accordingly, Lead

Plaintiff and Defendants agree not to assert any claim under Rule 11 of the Federal Rules of Civil

Procedure or any similar law, rule or regulation, that the Action were brought or defended in bad

faith or without a reasonable basis and further agree not to make any public statements that

contradict such position. The parties to this Settlement Stipulation agree that the amount paid and

the other terms of the Settlement were negotiated at arm's-length in good faith by the parties, and

reflect a settlement that was reached voluntarily based upon adequate information and after

consultation with experienced legal counsel.

28

38. The waiver by one party of any breach of this Settlement Stipulation by any other

party shall not be deemed a waiver of any other prior or subsequent breach of this Settlement

Stipulation.

39. This Settlement Stipulation and its exhibits constitute the entire agreement among

these parties, and no representations, warranties or inducements have been made to any party

concerning this Settlement Stipulation or its exhibits, other than the representations, warranties

and covenants contained and memorialized in such documents.

40. This Settlement Stipulation may be executed in one or more counterparts, including

by signature transmitted via facsimile, or by a .pdf/.tif image of the signature transmitted via

e-mail. All executed counterparts and each of them shall be deemed to be one and the same

instrument.

41. The parties hereto and their respective counsel of record agree that they will use

their best efforts to obtain all necessary approvals of the District Court required by this Settlement

Stipulation.

42. Each counsel signing this Settlement Stipulation represents that such counsel has

authority to sign this Settlement Stipulation on behalf of each of the Lead Plaintiff or Defendants,

as the case may be.

43. This Settlement Stipulation shall be binding upon and shall inure to the benefit of

the successors and assigns of the parties hereto, including any and all Released Persons and any

corporation, partnership, or other entity into or with which any party hereto may merge,

consolidate or reorganize.

44. Notices required by this Settlement Stipulation shall be submitted either by any

form of overnight mail or in person to:

29

Notice to Plaintiffs: Notice to Defendants:

Robert N. Kaplan Mark D. GatelyJoel B. Strauss Steven F. BarleyHae Sung Nam Scott R. HaiberAviah Cohen Pierson Nicholas G. StaylasKAPLAN FOX & KILSHEIMER LLP Jennifer A. Walker850 Third Avenue, 14th Floor HOGAN & HARTSON LLPNew York, NY 10022 111 South Calvert Street, Suite 1600Tel: (212) 687-1980 Baltimore, MD 21202Fax: (212) 687-7114 Tel: (410) 659-2700Email: RKaplan@KaplanFox.com Fax : (410) 539-6981

JStrauss@KaplanFox.com Email. MDGately@HHLAW.comHNam@KaplanFox.com SFBarley@HHLAW.comACohenPierson@KaplanFox.com SRHaiber@HHLAW.com

NGStavlas@HHLAW.comLead Counsel for Lead Plaintiff Sandra JAWalker@HHLAW.comAmrhein and the Proposed Class

Counsel for Defendants Sourcefire, Inc., E.Wayne Jackson, III, Thomas MMcDonough, Todd P. Headley, Martin F.Roesch, Asheem Chandna, Tim A. Guleri,Harry R. Weller, Steven R. Polk, Arnold L.Punaro and Joseph R. Chinnici

Robert T. CahillCOOLEY GOD WAR]) KRONISH LLPOne Freedom SquareReston Town Center11951 Freedom DriveReston, VA 20190-5656Tel: (703) 456-8000

Counsel for Defendants Sierra Ventures VII,LP and Tim A. Guleri

David Clarke, Jr.DLA PIPER LLP (US)500 Eighth Street, NWWashington, DC 20004Tel: (202) 799-4000

Counsel for Underwriter DefendantsMorgan Stanley & Co. Incorporated,Lehman Brothers Inc., UBS Securities LLC,and Jefferies & Company, Inc.

30

45. The terms of this Settlement Stipulation shall be governed by the laws of the State

of Maryland.

IN WITNESS WHEREOF, the parties hereto, intending to be legally bound

February L. 2009.

TYDINGS & RO N: G LLP/.411e

By ,1011211)AV AP'

hnTj°YD IN* P;Wr86' tRO-SEN-B- LLP100 East Pratt Street, 26 th FloorBaltimore, MD 21202Telephone: (410) 752-9714Facsimile: (410) 727-5460

Liaison Counsellor Lead Plaintiff andthe Proposed Class

KAPLAN FOX & KILSHEIMER LLP

By:

Robert N. KaplanKAPLAN FOX & KILSHEIMER LLP850 Third Avenue, 14th FloorNew York, NY 10022Tel: (212) 687-1980

Lead Counsel for Lead Plaintiff Sandra Amrhein andthe Proposed Class

31

45. The terms of this Settlement Stipulation shall be governed by the laws of the State

of Maryland.

IN WITNESS WHEREOF, the parties hereto, intending to be legally bound

February /7), 2009.

TYDINGS & ROSENBERG LLP

By:

John B. IsbisterTYDINGS & ROSENBERG LLP100 East Pratt Street, 26th FloorBaltimore, MD 21202Telephone: (410) 752-9714Facsimile: (410) 727-5460

Liaison Counsel for Lead Plaintiff andthe Proposed Class

KAPLAN )44' & KILSHEIMER LLP

By: !If..

Robert N. KaplanKAPLAN FOX & KILSHEIMER LLP850 Third Avenue, 14th FloorNew York, NY 10022Tel: (212) 687-1980

Lead Counsel for Lead Plaintiff Sandra Amrhein andthe Proposed Class

31

HOGAN & HARTSON LLP

By: ii‘diA

Mark D. GatelyHOGAN & HARTSON LLP111 South Calvert Street, Suite 1600Baltimore, MD 21202Tel: (410) 659-2700

Counsel for Defendants Sourcefire, Inc., E. WayneJackson, Ill, Thomas M. McDonough, Todd P. Headley,Martin F. Roesch, Asheem Chandna, Tim A. Guleri,Harry R. Weller, Steven R. Polk Arnold L. Punaro andJoseph R. Chinnici

COOLEY GODWARD KRONISH LLP

By:

Robert T. CahillCOOLEY GOD WARD ICRONISH LLPOne Freedom SquareReston Town Center11951 Freedom DriveReston, VA 20190-5656Tel: (703) 456-8000

Counsel for Defendants Sierra Ventures V11 LP andTim A. Guleri

DLA PIPER LLP (US)

By:

David Clarke, Jr.DLA PIPER LLP (US)500 Eighth Street, NWWashington, DC 20004Tel: (202) 799-4000

Counsel for Underwriter DefendantsMorgan Stanley & Co. Incorporated,Lehman Brothers Inc., UBS Securities LLC, andJefferies & Compcmy, Inc.

32

HOGAN & HARTSON LLP

By:

Mark D. GatelyHOGAN & HARTSON LLP111 South Calvert Street, Suite 1600Baltimore, MD 21202Tel: (410) 659-2700

Counsel for Defendants Sourcefire, Inc., E. WayneJackson, III, Thomas M McDonough, Todd P. Headley,Martin F. Roesch, Asheem Chandna, Tim A. Guleri,Harry R. Weller, Steven R. Polk, Arnold L. Punaro andJoseph R. Chinnici

COOLEY GOD , ONISH LLP

By:

Robert T. CahillCOOLEY GOD WARD KRONISH LLPOne Freedom SquareReston Town Center11951 Freedom DriveReston, VA 20190-5656Tel: (703) 456-8000

Counsel for Defendants Sierra Ventures VII, LP andTim A. Guleri

DLA PIPER LLP (US)

By:

David Clarke, Jr.DLA PIPER LLP (US)500 Eighth Street, NWWashington, DC 20004Tel: (202) 799-4000

Counsel for Underwriter DefendantsMorgan Stanley & Co. Incorporated,Lehman Brothers Inc., UBS Securities LLC, andJefferies & Company, Inc.

32

HOGAN & HARTSON LLP

By:

Mark D. GatelyHOGAN & HARTSON LLP111 South Calvert Street, Suite 1600Baltimore, MD 21202Tel: (410) 659-2700

Counsellor Defendants Sourcefire, Inc., E. WayneJackson, III, Thomas M. McDonough, Todd P. Headley,Martin F. Roesch, Asheem Chandna, Tim A. Guleri,Harry R. Weller, Steven R. Polk, Arnold L. Punaro andJoseph R. Chinnici

COOLEY GODWARD KRONISH LLP

By:

Robert T. CabinCOOLEY GODWARD KRONISH LLPOne Freedom SquareReston Town Center11951 Freedom DriveReston, VA 20190-5656Tel: (703) 456-8000

Counsel for Defendants Sierra Ventures VII, LP andTim A. Guleri

DLA PIPER LLP (US)

By: S.A.‘j CdLa/.4

David Clarke, Jr.DLA PIPER LLP (US)500 Eighth Street, NWWashington, DC 20004Tel: (202) 799-4000

Counsel for Underwriter DefendantsMorgan Stanley & Co. Incorporated,Lehman Brothers Inc., UBS Securities LLC, andJefferies & Company, Inc.

32

EXHIBIT A

UNITED STATES DISTRICT COURTDISTRICT OF MARYLAND

(Northern Division)

IN RE SOURCEFIRE, INC. SECURITIES Master File No. 07-cv-01210-JFMLITIGATION

JUDGE J. FREDERICK MOTZ

EXHIBIT A

[PROPOSED] ORDER PRELIMINARILY APPROVINGSETTLEMENT AND PROVIDING FOR NOTICE

WHEREAS, Lead Counsel on behalf of Lead Plaintiff Sandra Amrhein and the Class,

and Sourcefire, Inc. ("Sourcefire" or the "Company"), E. Wayne Jackson, III, Thomas M.

McDonough, Todd P. Headley, Martin F. Roesch, Asheem Chandna, Tim A. Guleri, Harry R.

Weller, Steven R. Polk, Arnold L. Punaro, Joseph R. Chinnici, Morgan Stanley & Co.

Incorporated, Lehman Brothers Inc., UBS Securities LLC, Jefferies & Company, Inc. and Sierra

Ventures VII, LP have entered into a settlement of the claims asserted in the Action, the terms of

which are set forth in a Stipulation and Agreement of Settlement, dated as of February 10, 2009

(the "Settlement Stipulation"), which is subject to review under Rule 23 of the Federal Rules of

Civil Procedure and which, together with the exhibits thereto, sets forth the terms and conditions

for the proposed settlement of the claims alleged in the Complaint filed in the Action and the

dismissal of the Action with prejudice, upon the terms and conditions set forth in the Settlement

Stipulation; and the District Court having read and considered the Settlement Stipulation, the

proposed Notice of Pendency of Class Action and Proposed Settlement, the proposed Summary

Notice of Pendency and Proposed Settlement of Class Action, the proposed Plan of Distribution

of Net Settlement Fund Among Class Members, the proposed form of the Proof of Claim and

Release, the proposed form of Order and Final Judgment relating to the Settlement and

submissions made relating thereto, and finding that substantial and sufficient grounds exist for

entering this Order; and capitalized terms used herein having the meanings defined in the

Settlement Stipulation;

NOW, THEREFORE, IT IS HEREBY ORDERED, this day of

2009, that:

1. Pursuant to Rule 23(a) and (b)(3) of the Federal Rules of Civil Procedure and for

the purposes of the Settlement only, the Action is hereby preliminarily certified as a class action

on behalf of all persons who purchased the publicly traded common stock of Sourcefire during

the period from March 9, 2007 through April 5, 2007, inclusive. Excluded from the Class are

any Released Persons.

2. The District Court finds, preliminarily and for purposes of Settlement only, that

the prerequisites for a class action under Rules 23(a) and (b)(3) of the Federal Rules of Civil

Procedure have been satisfied in that: (a) the number of the members of the Class is so

numerous that joinder of all members of those Class is impracticable; (b) there are questions of

law and fact common to each of the Class; (c) the claims of the Lead Plaintiff are typical of the

claims of the Class she seeks to represent; (d) the Lead Plaintiff will fairly and adequately

represent the interests of the Class; (e) the questions of law and fact common to the members of

the Class predominate over any questions affecting only individual members of the Class; and (f)

a class action is superior to other available methods for the fair and efficient adjudication of the

controversy.

2

3. Pursuant to Rule 23 of the Federal Rules of Civil Procedure, preliminarily and for

the purposes of Settlement only, Lead Plaintiff is certified as the class representative on behalf of

the Class and the Lead Counsel previously selected by Lead Plaintiff and appointed by the

District Court is hereby appointed as Lead Counsel for the Class.

4. A hearing (the "Settlement Fairness Hearing") pursuant to Federal Rule

of Civil Procedure 23(e) is hereby scheduled to be held before the District Court on

, at for the following purposes:

(a) to finally determine whether the Action satisfies the applicable

prerequisites for class action treatment under Federal Rules of Civil Procedure 23(a) and (b);

(b) to determine whether the Settlement is fair, reasonable, and adequate, and

should be approved by the District Court;

(c) to determine whether the Order and Final Judgment as provided under the

Settlement Stipulation should be entered, dismissing the Complaint, on the merits and with

prejudice, and to determine whether the release by the Class Members of the Released Persons,

as set forth in the Settlement Stipulation, should be ordered;

(d) to determine whether the proposed Plan of Distribution for the proceeds of

the Settlement is fair and reasonable and should be approved by the District Court;

(e) to consider the application of Lead Counsel for an award of attorneys' fees

and reimbursement of expenses; and

to rule upon such other matters as the District Court may deem appropriate.

5. The District Court reserves the right to approve the Settlement with or without

modification and with or without further notice of any kind. The District Court further reserves

the right to enter its Order and Final Judgment approving the Settlement Stipulation and

3

dismissing the Complaint, on the merits and with prejudice, regardless of whether it has

approved the Plan of Distribution or awarded attorneys' fees and expenses.

6. The District Court approves the form, substance and requirements of (a) the

Notice of Pendency of Class Action and Proposed Settlement (the "Notice"), and (b) the Proof of

Claim and Release form (the "Proof of Claim"), both of which are annexed hereto as Exhibits 1

and 2 respectively.

7. Lead Counsel has the authority to enter into the Settlement Stipulation on behalf

of the Class and is authorized to act on behalf of the members of the Class with respect to all acts

or consents required by or that may be given pursuant to the Settlement Stipulation or such other

acts that are reasonably necessary to consummate the Settlement.

8. Lead Counsel shall cause the Notice and the Proof of Claim, substantially in the

forms annexed hereto, to be mailed, by first class mail, postage prepaid, within 10 calendar days

of the entry of this Order ("Notice Date"), to all members of the Class who can be identified with

reasonable effort by Lead Counsel.

9. Lead Counsel are authorized to establish a Notice and Administration Fund (as

defined in the Settlement Stipulation) of $100,000 to be used for reasonable out-of-pocket costs

in connection with providing notice of the Settlement to the Class and for other reasonable out-

of-pocket administrative expenses. Upon written agreement of the parties, or order of the

District Court, additional amounts may be transferred from the Settlement Fund to the Notice

and Administration Fund.

10. Lead Counsel or their designated agent shall also make reasonable efforts to give

notice to nominee owners such as brokerage firms and other persons or entities who purchased

Sourcefire common stock during the Class Period. Such nominee purchasers are directed to

4

forward copies of the Notice and Proof of Claim to their beneficial owners or to provide the

Claims Administrator with lists of the names and addresses of the beneficial owners and the

Claims Administrator is ordered to send the Notice and Proof of Claim promptly to such

beneficial owners. Additional copies of the Notice shall be made available to any record holder

requesting same for the purpose of distribution to beneficial owners, and such record holders

shall be reimbursed from the Settlement Fund, upon receipt by the Claims Administrator of

proper documentation, for the reasonable expense of sending the Notices and Proof of Claim to

beneficial owners. Lead Counsel shall, at or before the Settlement Fairness Hearing, serve upon

Defendants' Counsel, and file with the District Court, proof of mailing of the Notice and Proof of

Claim.

11. The District Court approves the form of the Summary Notice of Pendency

of Class Action and Proposed Settlement (the "Publication Notice") in substantially the form

and content annexed hereto as Exhibit 3 and directs that Lead Counsel shall cause

the Publication Notice to be published in Wall Street Journal and on the Internet at

wwvv.sourcefiresecuritieslitigation.com within 5 calendar days of the Notice Date. Lead Counsel

shall, at or before the Settlement Fairness Hearing, serve upon Defendants' Counsel and file with

the District Court proof of publication of the Publication Notice.

12. The form and method set forth herein of notifying the Class of the Settlement

and its terms and conditions meet the requirements of due process and Rule 23 of the Federal

Rules of Civil Procedure constitute the best notice practicable under the circumstances, and shall

constitute due and sufficient notice to all persons and entities entitled thereto.

13. In order to be entitled to participate in the Net Settlement Fund, as defined in the

Settlement Stipulation, in the event the Settlement is effected in accordance with all of the terms

5

and conditions thereof, each Class Member shall take the following action and be subject to the

following conditions:

(a) A properly executed Proof of Claim (the "Proof of Claim"), substantially

in the form attached hereto as Exhibit 2, must be submitted to the Claims Administrator, at the

Post Office Box indicated in the Notice, postmarked not later than ninety (90) days from the

Notice Date. Such deadline may be further extended by Order of the District Court. Each Proof

of Claim shall be deemed to have been submitted when postmarked (if properly addressed and

mailed by first class mail) provided such Proof of Claim is actually received prior to the filing of

a motion for an Order of the District Court approving distribution of the Net Settlement Fund.

Any Proof of Claim submitted in any other manner shall be deemed to have been submitted

when it was actually received at the address designated in the Notice.

(b) The Proof of Claim submitted by each Class Member must satisfy the

following conditions: (i) it must be properly filled out, signed and submitted in a timely manner

in accordance with the provisions of the preceding subparagraph; (ii) it must be accompanied by

adequate supporting documentation for the transaction reported therein, in the form of broker

confirmation slips, broker account statements, an authorized statement from the broker

containing the transactional information found in a broker confirmation slip, or such other

documentation as is deemed adequate by Lead Counsel; (iii) if the person executing the Proof of

Claim is acting in a representative capacity, a certification of his current authority to act on

behalf of the Class Member must be included in the Proof of Claim; and (iv) the Proof of Claim

must be complete and contain no material deletions or modifications of any of the printed matter

contained therein and must be signed under penalty of perjury.

6

(c) Once the Claims Administrator has considered a timely submitted Proof of

Claim, Lead Counsel, through the Claims Administrator, shall determine, based upon the Plan of

Distribution of Net Settlement Fund, whether such claim is valid, deficient or rejected. For each

claim determined to be either deficient or rejected, the Claims Administrator shall send a

deficiency letter or rejection letter as appropriate, describing the basis on which the claim was so

determined.

(d) As part of the Proof of Claim, each Class Member shall submit to the

jurisdiction of the District Court with respect to the claim submitted.

14. Members of the Class shall be bound by all determinations and judgments in the

Action, whether favorable or unfavorable, unless such persons request exclusion from the Class

in a timely and proper manner, as hereinafter provided. A member of the Class wishing to make

such request shall mail the request in written form, by first class mail, postage prepaid, and

postmarked no later than forty-five days from the Notice Date to the Post Office Box address

listed in the Notice. Such request for exclusion shall clearly indicate the name and address of the

person seeking exclusion, that the sender specifically requests to be excluded from the Class (as

defined in the Settlement Stipulation) and must be signed by such person. Such persons

requesting exclusion are also required to specify all purchases of the Sourcefire common stock

during the Class Period, including the number and price of the shares purchased during the Class

Period, the number and price of shares sold from March 9, 2007 to July 26, 2007, and the date of

each such purchase or sale. It is also requested that such persons provide their telephone number

or other contact information. The request for exclusion shall not be effective unless the request

for exclusion provides the required information and is made within the time stated above, or the

exclusion is otherwise accepted by the District Court.

7

15. Members of the Class requesting exclusion from the Class shall not be entitled to

receive any payment out of the Net Settlement Fund as described in the Settlement Stipulation

and Notice.

16. The District Court will consider comments and/or objections to the Settlement,

the Plan of Distribution, or the award of attorneys' fees and reimbursement of expenses only if

such comments or objections and any supporting papers are served at least forty-five days from

the Notice Date, upon each of the following: (i) Kaplan Fox & Kilsheimer LLP, Robert N.

Kaplan, Esq., Aviah Cohen Pierson, Esq., 850 Third Avenue, New York, NY 10022 (Lead

Counsel for Lead Plaintiff and the Class); (ii) Tydings & Rosenberg LLP, John Isbister, 100 East

Pratt Street, 26th Floor, Baltimore, MD 21202; (iii) Hogan & Hartson LLP, Mark Gately, Esq.,

111 South Calvert Street, Suite 1600, Baltimore, MD 21202 (on behalf of Defendants);

(iv) Cooley Godward Kronish LLP, Robert T. Cahill, Esq., One Freedom Square, Reston Town

Center, 119 Freedom Drive, Reston, VA 20190-5656 (on behalf of Tim A. Guleri and Sierra

Ventures VII, LP); and (v) DLA Piper LLP (US), David Clarke, Jr., Esq., 500 Eighth Street, NW,

Washington, DC 20004 (on behalf of the Underwriter Defendants). The objector has filed said

objections, papers and briefs, showing due proof of service upon counsel identified above, with

the Clerk of the Court, U.S. District Court, District of Maryland, 101 West Lombard Street,

Baltimore, MD 21201. Attendance at the hearing is not necessary; however, persons wishing to

be heard orally in opposition to the approval of the Settlement, the Plan of Distribution, and/or

Lead Counsel's request for attorneys' fees are required to indicate in their written objection their

intention to appear at the hearing. Persons who intend to object to the Settlement, the Plan of

Distribution, and/or Lead Counsel's application for award of attorneys' fees and reimbursement

of expenses and desire to present evidence at the Settlement Fairness Hearing must include in

8

their written objections the identity of any witnesses they may call to testify and exhibits they

intend to introduce into evidence at the Settlement Fairness Hearing. Class Members do not

need to appear at the hearing or take any other action to indicate their approval.

17. Any Class Member who does not object in the manner prescribed above shall be

deemed to have waived all such objections and shall forever be foreclosed from making any

objection to the fairness, adequacy or reasonableness of the Settlement, the Order and Final

Judgment to be entered approving the Settlement, the Plan of Distribution, or Lead Counsel's

application for an award of attorneys' fees and reimbursement of expenses.

18. The District Court reserves the right to adjourn the Settlement Fairness Hearing or

any adjournment thereof without any further notice other than an announcement at the

Settlement Fairness Hearing or any adjournment thereof, and to approve the Settlement without

further notice to the Class.

19. All papers in support of the Settlement, the Plan of Distribution and any

application for attorneys' fees or expenses shall be filed and served thirty (30) calendar days

prior to the Settlement Fairness Hearing.

20. Pending final determination of whether the Settlement should be approved, all

Class Members, and each of them, and anyone who acts or purports to act on their behalf shall

not institute, commence or prosecute any action which asserts Released Claims against any of

the Released Persons.

21. In the event that the Settlement shall not be consummated pursuant to its terms,

the Settlement Stipulation, except as otherwise provided therein, including any amendment(s)

thereto, and this Order Preliminarily Approving Settlement and Providing For Notice, shall be

null and void, of no further force or effect, and without prejudice to any party, and may not be

9

introduced as evidence or referred to in any action or proceedings by any person or entity, and

each party shall be restored to his, her or its respective position as it existed prior to the

execution of the Settlement Stipulation.

22. The District Court retains exclusive jurisdiction over the action to consider all

further matters arising out of, or connected with, the Settlement.

Dated: Baltimore, Maryland , 2009

United States District Judge J. Frederick Motz

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EXHIBIT A-1

UNITED STATES DISTRICT COURTDISTRICT OF MARYLAND

(Northern Division)

IN RE SOURCEFIRE, INC. SECURITIES Master File No. 07-cv-01210-JFMLITIGATION

JUDGE J. FREDERICK MOTZ

EXHIBIT A-1

NOTICE OF PENDENCY OF CLASS ACTION AND PROPOSED SETTLEMENT

A Federal Court authorized this Notice. This is not a solicitation from a lawyer.

PLEASE READ THIS NOTICE CAREFULLY!

THIS NOTICE EXPLAINS IMPORTANT RIGHTS YOU MAY HAVEINCLUDING YOUR POSSIBLE RECEIPT OF CASH FROM THESETTLEMENT. YOUR LEGAL RIGHTS ARE AFFECTED WHETHER YOUDO OR DO NOT ACT. IN ORDER TO RECOVER FROM THE SETTLEMENT,YOU MUST FILE A PROOF OF CLAIM AND RELEASE POSTMARKED ON ORBEFORE , 2009.

If you purchased the publicly traded common stock of Sourcefire, Inc. ("Sourcefire CommonStock") between March 9, 2007 to April 5, 2007, inclusive (the "Class Period"), you are a member of theClass ("Class") and could get a payment from the Settlement described below. You are a Class Memberunless you have filed a valid and timely request for exclusion in accordance with the requirements setforth in this Notice (see 52).

1. Statement of Class' Recovery: This Notice has been sent to you pursuant to an Order ofthe United States District Court for the District of Maryland (the "Court") in the class actionsconsolidated under the caption In re Sourcefire, Inc. Securities Litigation, No. 07-cv-01210-FM (the"Action"). The purpose of this Notice is to inform you of the proposed Settlement of the Action for$3,200,000 in cash. This Notice describes the rights you may have in connection with the Settlement,what steps you may take in relation to the Settlement, and provides information about the hearing that willbe held by the Court to consider the fairness, reasonableness and adequacy of the Settlement. In order toreceive proceeds from the Settlement, you will need to file a Proof of Claim and Release.

2. Reasons for the Settlement: The Settlement resolves claims against Defendants (asdefined herein) in the Action regarding alleged violations of the federal securities laws. The Defendants

deny all allegations of wrongdoing. hi light of the amount of the Settlement and the immediacy ofrecovery to the Class, Lead Plaintiff believes that the proposed Settlement is fair, reasonable and adequate,and in the best interests of the Class. The Settlement provides $3,200,000 in cash as compared to the riskthat a similar, smaller or no recovery would be achieved after a trial and appeals, possibly years in thefuture, in which the Defendants would have the opportunity to assert defenses to the claims assertedagainst them.

3. Statement of Average Amount of Damage Per Share: Lead Plaintiff and theDefendants do not agree on the average amount of damages per share that would be recoverable if LeadPlaintiff had prevailed on each claim alleged. The issues on which the parties disagree include, but arenot limited to: (a) the appropriate economic model for determining the amount by which SourcefireCommon Stock was allegedly artificially inflated (if at all) during the Class Period; (b) the amount bywhich Sourcefire Common Stock was allegedly artificially inflated (if at all) during the Class Period;(c) the various market forces influencing the trading price of Sourcefire Common Stock at various timesduring the Class Period; (d) the extent to which external factors, such as general market conditions,influenced the trading price of Sourcefire Common Stock at various times during the Class Period; (e) theextent to which the various matters that Lead Plaintiff alleged were false or misleading influenced (if atall) the trading price of Sourcefire Common Stock at various times during the Class Period; (f) the extentto which the various allegedly material facts that Lead Plaintiff alleged were omitted influenced (if at all)the trading price of Sourcefire Common Stock at various times during the Class Period; and (g) whetherthe statements allegedly made or facts allegedly omitted were actionable under the federal securities laws.

Lead Plaintiff's damages expert estimates that approximately 6,761,937 shares ofSourcefire Common Stock traded during the Class Period and were damaged. Based upon the Plan ofDistribution discussed below, and assuming that the owners of all damaged Sourcefire Common Stockelect to participate in the Settlement, the average recovery per share could be approximately $0.473, orapproximately 23.5% of recoverable damages, before deduction of any fees, expenses, costs and awardsdescribed herein. The actual amount disbursed to Class Members who submit timely and valid Proofs ofClaim and Releases ("Authorized Claimants") may be more or less than this figure.

4. Statement of Attorneys' Fees and Expenses: Lead Counsel has not received anypayment for its services in conducting this litigation on behalf of Lead Plaintiff and the Class, nor has itbeen reimbursed for its out-of-pocket expenditures. If the Settlement is approved by the Court, LeadCounsel will apply to the Court for attorneys' fees not to exceed 30% of the settlement proceeds andreimbursement of expenses not to exceed $100,000 to be paid from the settlement proceeds. If theamount requested by Lead Counsel is approved by the Court, the average cost would not exceed $0.157per share. The Court shall decide the reasonableness of the fees and reimbursement of expenses.

5. Identification of Lead Plaintiffs Representatives: For further information regardingthis settlement you may contact Aviah Cohen Pierson, Kaplan Fox & Kilsheimer LLP, 850 Third Avenue,New York, NY 10022. The telephone number is (212) 687-1980. DO NOT CONTACT THE COURT.

YOUR LEGAL RIGHTS AND OPTIONS IN THIS SETTLEMENTDATE

SUBMIT A PROOF OF CLAIM AND The only way to get a payment that results in theRELEASE FORM

release of claims against the Defendants and others.(See 411$ 43-51)

EXCLUDE YOURSELF Get no payment. This is the only option that allowsyou to ever be part of any other lawsuit against theDefendants with respect to the claims in this case.(See 1[1[ 52-54)

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YOUR LEGAL RIGHTS AND OPTIONS IN THIS SETTLEMENTDATE

TELL THE COURT YOUR VIEWS Write to the Court and explain why you do not likeor like the Settlement. (See 57-61)

REQUEST NOTICE OF CHANGE You may request to be notified if the Plan ofOF PLAN OF DISTRIBUTION

Distribution of the Settlement is modified in anymanner. (See 39)

GO TO A HEARING

Ask to speak in Court about the fairness of theSettlement. (See VI 57-61)

DO NOTHING Get no payment. Give up your rights (releaseclaims). (See im 47-51). Alternatively, submit aclaim. (See 41f1 43-46)

WHY DID I GET THIS NOTICE?

6. You or someone in your family may have purchased shares of Sourcefire Common Stockduring the Class Period. The Court sent you this Notice because, as a potential Class Member, you have aright to know about a proposed Settlement of the Action and your options, before the Court decideswhether to approve the Settlement. A class action is a lawsuit in which one or more persons sue on behalfof all other persons who have similar claims.

7. If the Court approves the Settlement, and after any objections and appeals are resolved, aclaims administrator approved by the Court will make payments from the Settlement Fund to eligibleclaimants pursuant to the Settlement.

8. The Court in charge of this case is the United States District Court for the District ofMaryland, and the case is known as In re Sourcefire, Inc. Securities Litigation, No. 07-cv-01210-JFM.The plaintiff in this lawsuit is the Court-appointed Lead Plaintiff, Sandra Amrhein. The entities andpeople who have been sued are Sourcefire, Inc. ("Sourcefire" or the "Company"), E. Wayne Jackson, III,Thomas M. McDonough, Todd P. Headley, Martin F. Roesch, Asheem Chandna, Tim A. Guleri, Harry R.Weller, Steven R. Polk, Arnold L. Punaro, Joseph R. Chinnici, Morgan Stanley & Co. Incorporated,Lehman Brothers Inc., UBS Securities LLC, Jefferies & Company, Inc. and Sierra Ventures VII, LP(collectively, the "Defendants"). This settlement would settle and release all claims against theDefendants. Your interests have been represented in this lawsuit by Court-appointed Lead Counsel,Kaplan Fox & Kilsheimer LLP, 850 Third Avenue, New York, NY 10022 ("Lead Counsel" or "KaplanFox").

9. This Notice explains the lawsuit, the Settlement, your legal rights, what benefits areavailable, who is eligible for them, and how to get them. The purpose of this Notice is to inform you ofthe terms of the proposed Settlement and to inform you of a hearing to be held by the Court to considerthe fairness, reasonableness, and adequacy of the proposed Settlement and to consider the application forattorneys' fees and reimbursement of litigation expenses.

10. The Settlement Hearing will be held on , 2009, at before the Honorable J. Frederick Motz, United States District Judge of the District of Maryland,101 West Lombard Street, Baltimore, MD 21201 (the "Settlement Hearing"). The purpose of theSettlement Hearing will be to determine: (a) whether the settlement for $3,200,000 in cash should beapproved as fair, just, reasonable and adequate to Lead Plaintiff and the Class Members; (b) whether theproposed plan to distribute the Settlement proceeds (the "Plan of Distribution") is fair, just, reasonable

3

and adequate; (c) whether the application by Lead Counsel for an award of attorneys' fees and expensesshould be approved and the extent of a reasonable fee; and (d) whether the Action should be dismissedwith prejudice against the Defendants.

11. The Court may adjourn or continue the Settlement Hearing without further notice to theClass. The issuance of this Notice is not an expression of the Court's opinion on the merits of any claimin the lawsuit, and the Court still has to decide whether to approve the Settlement. If the Court approvesthe Settlement, payments will be made after appeals, if any, are resolved and after the processing of allclaims. Please be patient.

HOW DO I KNOW IF I AM PART OF TIM SETTLEMENT?

12. By order of the Court dated , 2009, all persons who purchasedthe publicly traded common stock of Sourcefire during the period from March 9, 2007 through April 5,2007, inclusive were certified as the Class. Excluded from the Class are any Released Persons. "ClassMembers" refer to the members of the Class who have not excluded themselves from the Settlement byfiling a request for exclusion in accordance with the requirements set forth in this Notice (see 5 52).

RECEIPT OF THIS NOTICE DOES NOT NECESSARILY MEAN THAT YOUARE A CLASS MEMBER OR ARE ENTITLED TO RECEIVE PROCEEDSFROM THE SETTLEMENT. IF YOU WISH TO PARTICIPATE IN THESETTLEMENT, YOU MUST MAIL THE PROOF OF CLAIM AND RELEASE,POSTMARKED ON OR BEFORE , 2009, (SEE 55 43-51).

WHAT RECOVERY DOES THE SETTLEMENT PROVIDE?

13. The total monetary value of the Settlement is $3,200,000 in cash (the "SettlementAmount"). Attorneys' fees and expenses, notification costs, and claim administration costs will bededucted from the Settlement Amount. The Settlement Amount minus these fees, costs, expenses, andawards (the "Distribution Amount") shall be distributed to Class Members.

14. The average expected recovery will depend on a number of factors including when andfor what price Class Members purchased and/or sold their shares of Sourcefire Common Stock, and thetotal number of shares for which timely and valid Proofs of Claim and Releases are submitted byAuthorized Claimants.

WHY IS THERE A SETTLEMENT?

15. Under the proposed Settlement, the Court will not decide in favor of either the LeadPlaintiff or the Defendants. By agreeing to a Settlement, both the Lead Plaintiff and the Defendants avoidthe costs and risk of a trial, and the Class Members are compensated.

16. In light of the amount of the Settlement and the immediacy of recovery to the Class, LeadPlaintiff believes that the proposed Settlement is fair, reasonable and adequate, and in the best interests ofClass. The Settlement provides a substantial benefit, namely $3,200,000 in cash, as compared to the riskthat a similar, smaller or no recovery would be achieved after a trial and appeals, possibly years in thefuture, in which the Defendants would have the opportunity to assert defenses to the claims assertedagainst them.

4

WHAT MIGHT HAPPEN IF THERE WERE NO SETTLEMENT?

17. If there were no Settlement and Lead Plaintiff failed to establish any essential legal orfactual element of its claims, neither Lead Plaintiff nor the Class would recover anything from theDefendants. Also, if the Defendants were successful in proving any of their defenses, the Class likelywould recover substantially less than the amount provided in the Settlement, or nothing at all.

WHAT IS THIS CASE ABOUT? WHAT HAS HAPPENED SO FAR?

Background

18. Sourcefire describes itself as a "leading provider of intelligence driven, open sourcenetwork security solutions that enable our customers to protect their computer networks in aneffective, efficient and highly automated manner." The Company was founded in 2001 by DefendantRoesch who authored a technology known as Snort. Sourcefire incorporates SNORT technology into itsnetwork intrusion detection and prevention appliances. The Company sells its products "to a diversecustomer base that includes more than 25 of the Fortune 100 companies and over half of the 30largest U.S. government agencies." Some of its clients include the Department of Homeland Security,the Department of the Army, Immix Group, Verisign, Verizon Business, Lockheed Martin, Citigroup,Northrup Grumman, Symantec and Nokia.

19. On March 9, 2007, Sourcefire completed an initial public offering ("IPO"), issuing5,770,000 shares of common stock of the Company at $15.00 per share pursuant to a registrationstatement. On March 22, 2007, the Company disclosed the Exercise of an Over-Allotment Option inConnection with its IPO. The Company stated: "Morgan Stanley & Co. Incorporated, who acted as thesole book-running manager for the recent initial public offering, has exercised in full their over-allotmentoption to purchase an additional 865,500 shares of Sourcefire common stock, bringing the total proceedsreceived by Sourcefire in the offering to approximately $86.3 Million."

20. On Friday, April 6, 2007, Sourcefire issued a press release announcing disappointingpreliminary results for the quarter ended March 31, 2007. The Company stated "Revenues for the firstquarter of 2007 are estimated to be in the range of $10.1 to $10.5 million compared to $8.5 million in thefirst quarter of 2006. Gross profit for the first quarter of 2007 is estimated to be $7.8 to $8.2 million,compared to $6.5 million in the first quarter of 2006. The Company's GAAF' net loss for the first quarterof 2007 is estimated to be $2.2 to $2.6 million."

The Action

21. Beginning May 8, 2007, a number of Sourcefire investors filed the following putativesecurities class actions against Sourcefire., certain of its executives and the underwriters of Sourcefire'sIPO:

Case Civil No.1. Howard Katz v. Source/Ire, Inc., et al. 07-CV-012102. Mark Reaves v. Source/Ire, Inc., et al. 07-CV-013513. Joan Raveill v. Source/Ire, Inc., etal. 07-CV-014254. Barry Pincus v. Source/Ire, Inc., et al. 07-CV-02048

5

22. On July 13, 2007, Sandra Amrhein and other Sourcefire investors moved pursuant to thePrivate Securities Litigation Reform Act of 1995 ("PSLRA") to: 1) consolidate the cases; 2) appointLead Plaintiff; and 3) appoint lead counsel. By an Order dated September 4, 2007, the District Courtconsolidated the above-captioned cases for all purposes under the caption In re Sourcefire, Inc. SecuritiesLitigation, Case No. 07-CV-01210, appointed Sandra Amrhein as Lead Plaintiff and appointed the lawfirm of Kaplan Fox as Lead Counsel.

23. On October 4, 2007, Lead Plaintiff filed an Amended Consolidated Class ActionComplaint (the "Complaint") alleging violations of Sections 11, 12 and 15 of the Securities Act of 1933(the "Securities Act"). The Complaint was brought on behalf of a purported class of all persons orentities who purchased the common stock of Sourcefire pursuant and/or traceable to the Company'sregistration statement and prospectus issued in connection with Sourcefire's March 9, 2007 1P0.

The Claims

24. The Complaint alleges that the registration statement/prospectus filed by Sourcefire withthe Securities and Exchange Commission for the Company's IPO was false and misleading for failing todisclose that sales of Sourcefire's products to the federal government and revenues from the federalgovernment had materially decreased; and that Sourcefire's first calendar quarter had historicallybeen the Company's slowest quarter.

Procedural History

25. On November 20, 2007, each Defendant moved pursuant to Rule 12(b)(6) of the FederalRules of Civil Procedure and the PSLRA to dismiss the Complaint. On April 23, 2008, the Court deniedin part and granted in part Defendants' motions to dismiss.

26. On June 18, 2008, Plaintiffs moved the Court to certify a class and appoint SandraAtnrhein as Class Representative and Kaplan Fox as Counsel to the Class.

Events that Led to the Settlement

27. The parties to the Settlement Stipulation engaged in a mediation session before Hon.Daniel Weinstein (Ret.), a well-known mediator of disputes of this nature, concerning the possibility ofsettlement. The mediation, held in New York City on October 17, 2008, did not immediately result insettlement of the Action. However, the parties continued to engage in settlement discussions after theformal mediation session ended. Following arms-length negotiations for a lengthy period of time, withthe assistance of Judge Weinstein, Lead Plaintiff and the Defendants entered into a Stipulation ofSettlement ("Settlement Stipulation") on , 2009. A copy of the SettlementStipulation has been filed with the Court.

28. Throughout the settlement negotiations, various consultants and experts, includingindividuals with expertise in estimating potential damages in cases involving allegations of securities lawviolations, advised the Lead Plaintiff.

WHAT ARE THE LEAD PLAINTIFF'S REASONS FOR THE SETTLEMENT?

29. Lead Plaintiff believes that the claims have merit and that the evidence developed to datesupports those claims. However, Lead Plaintiff recognizes and acknowledges the expense and length of

6

continued proceedings, trial and appeals. Lead Plaintiff also has taken into account the uncertain outcomeand the risk of any litigation, especially in complex actions such as the Action, as Lead Plaintiff is alsomindful of the inherent problems of proof under and possible defenses to the federal securities lawviolations asserted in the Action, including the defenses asserted by Defendants during the litigation, inmotions and on the pleadings, and in settlement negotiations.

30. The Settlement was reached as part of arms-length negotiations before an experiencedmediator concerning the parties' divergent views about the merits and value of the claims.

31. In light of the foregoing, Lead Plaintiff believes that the Settlement set forth in theSettlement Stipulation confers substantial benefits upon the Class. Based on her evaluation, LeadPlaintiff has determined that the Settlement set forth in the Settlement Stipulation is in the best interests ofthe Class.

WHY HAVE DEFENDANTS AGREED TO THE SETTLEMENT?

32. The Defendants have denied and continue to deny each and all of the claims andcontentions alleged by the Lead Plaintiff on behalf of the Class. The Defendants also have denied andcontinue to deny, among other things, the allegations that the price of Sourcefire Common Stock wasartificially inflated by reasons of alleged misrepresentations, non-disclosures or otherwise, or that anyharm was caused by the conduct alleged. The Defendants believe that they fully disclosed their trueopinions about Sourcefire and made no misrepresentations of material facts.

33. Nonetheless, the Defendants have concluded that further conduct of the Action would beprotracted and expensive, and that it is desirable that the Action be fully and finally settled in the mannerand upon the terms and conditions set forth in the Settlement Stipulation in order to limit further expense,inconvenience and distraction, to dispose of the burden of protracted litigation, and to permit theoperation of the Defendants' businesses without further distraction and diversion caused by continuationof the Action. The Defendants also have taken into account the uncertainty and risks inherent in anylitigation, especially in complex cases such as this litigation.

34. The Defendants have, therefore, determined that it is desirable and beneficial to them thatthe Action be settled in the manner and upon the terms and conditions set forth in the SettlementStipulation. The Defendants entered into the Settlement Stipulation without in any way acknowledgingany fault, liability, or wrongdoing of any kind.

HOW MUCH WILL MY PAYMENT BE? WHAT IS THE PLAN OF DISTRIBUTION?

35. Your share (if any) of the recovery will depend on the number of valid Proofs of Claimand Releases that Class Members send in, how many shares of Sourcefire Common Stock you bought,and when you bought and sold your shares.

36. The settlement amount is $3,200,000 in cash. Attorneys' fees and expenses, notificationcosts and claims administration costs will be deducted from the Settlement Amount. The SettlementAmount minus these fees, costs, expenses and awards shall be distributed to the Class Members.

37. To receive a portion of the Distribution Amount, Class Members must complete a Proofof Claim and Release and mail it and all required documentation to the Claims Administratorpostmarked on or before , 2009. Class Members who do not submit

7

acceptable Proofs of Claim and Releases will not share in the settlement proceeds. Class Members (Le.,members of the Class who do not submit a request for exclusion) who do not submit an acceptable Proofof Claim and Release will nevertheless be bound by the Settlement and the Final Judgment and Order ofDismissal of the Court ("Final Judgment"), dismissing the claims against the Defendants.

38. A claim will be calculated as follows:

For shares of common stock acquired in the March 9, 2007 IPO and/or purchased on theopen market between March 9, 2007 and April 5, 2007:

A. For shares retained at the end of trading on July 26, 2007, the Recognized Lossshall be the lesser of:

(1) $1.95 per share'; or(2) the difference between the purchase price per share and $13.05.

B. For shares sold between March 9, 2007 and April 5, 2007, the Recognized Lossshall be zero.

C. For shares sold between April 9, 2007 and May 8, 2007, the Recognized Lossshall be the difference between (a) the lesser of (i) $15.00 or (ii) purchase priceper share; and (b) the sales price per share for each share sold.

D. For shares sold between May 9, 2007 and July 26, 2007, the Recognized Lossshall be the lesser of:

(1) $1.95 per share; or(2) the difference between (a) the lesser of (i) $15.00 or (ii) purchase price

per share; and (b) the sales price per share for each share sold.

In processing claims, the first-in, first-out basis will be applied to purchases and sales. Apurchase or sale of Sourcefire common stock shall be deemed to have occurred on the "contract" or"trade" date as opposed to the "settlement" or "payment" date. The receipt or grant by gift, devise oroperation of law of Sourcefire common stock during the Class Period shall not be deemed a purchase orsale of Sourcefire common stock for the calculation of an Authorized Claimant's Recognized Loss norshall it be deemed an assignment of any claim relating to the purchase of such shares unless specificallyprovided in the instrument of gift or assignment. To the extent a Claimant had a gain from his, her or itsoverall transactions in Sourcefire common stock under the Plan of Distribution, the value of theRecognized Claim will be zero. To the extent that a Claimant suffered an overall loss on his, her or its

$1.95 is the difference between $15.00 (Sourcefire's IPO price) and $13.05, the closing price of Sourcefire,Inc. common stock on May 8, 2007, the date on which a lawsuit was first filed in this matter. Generally, themaximum amount which purchasers may recover in a lawsuit filed under Section 11 is the difference between theamount paid for the security (not exceeding the price at which the security was offered to the public) and (1) thevalue thereof as of the time such suit was brought, or (2) the price at which such security shall have been disposed ofin the market before suit, or (3) the price at which such security shall have been disposed of after suit but beforejudgment if such damages shall be less than the damages representing the difference between the amount paid forthe security (not exceeding the price at which the security was offered to the public) and the value thereof as of thetime such suit was brought. July 26, 2007 was the last date on which the closing price of Sourcefire, Inc. commonstock exceeded $13.05 per share.

8

overall transactions in Sourcefire common stock during the Class Period, but that loss was less than theRecognized Loss calculated above, then the Recognized Claim shall be limited to the amount of the actualloss. For purposes of determining whether a Claimant had a gain from his, her or its overall transactionsin Sourcefire common stock during the Class Period or suffered a loss, the Claims Administrator shall: (i)total the amount paid for all Sourcefire common stock purchased during the Class Period by the claimant(the "Total Purchase Amount"); (ii) total the amount received for sales of the remaining shares ofSourcefire common stock sold from March 9, 2007 through July 26, 2007 (the "Sales Proceeds") and (iii)ascribe a $13.05 per share holding value "the "Holding Value" for the number of shares of Sourcefirecommon stock purchased during the Class Period and still held at the end of trading on July 26, 2007. Thedifference between (x) the Total Purchase Amount ((i) above) and (y) the sum of the Sales Proceeds ((ii)above) and the Holding Value ((iii) above) will be deemed a Claimant's gain or loss on his, her or itsoverall transactions in Sourcefire common stock during the Class Period. The difference between (x) theTotal Purchase Amount ((i) above) and (y) the Sales Proceeds ((ii) above) will be deemed a Claimant'sgain or loss on his, her or its overall transactions in Sourcefire common stock during the Class Period.

No payment will be made on any claim where the potential distribution amount is $10.00 or less, but theClaimant will otherwise be bound by the Final Judgment entered by the Court.

39. Lead Plaintiff may alter the Plan of Distribution plan set forth in 138 (subject to Courtapproval) without any further notice to Class Members, unless such Class Members expressly requestnotice of alteration of the Plan of Distribution. Therefore, in order to receive such notice, you must send arequest no later than , 2009 by contacting the Claims Administrator as setforth below.

40. The Court has reserved jurisdiction to allow, disallow, or adjust the claim of any ClassMembers on equitable grounds.

41. No person shall have any claim against Lead Plaintiff's Counsel, the ClaimsAdministrator or other agent designated by Lead Plaintiff's Counsel, or any Defendant or anyDefendants' counsel based on any distribution made substantially in accordance with the SettlementStipulation and the Plan of Distribution, or further orders of the Court.

42. The Court also may modify the Plan of Distribution without further notice to ClassMembers.

HOW DO I PARTICIPATE IN THE SETTLEMENT? WHAT DO I NEED TO DO?

43. If you fall within the Class as defined above, you will remain a Class Member unless youelect to be excluded therefrom. If you do not request to be excluded from the Class, you will be bound byany judgment entered in the Action whether or not you file a Proof of Claim and Release, including thedismissal with prejudice of any Released Claims (as defined in Section VII of the Proof of Claim andRelease) you may possess against the Defendants under Federal law, or the law of any state.

44. If you wish to remain a Class Member, you need do nothing (other than timely requestand file a Proof of Claim and Release if you wish to participate in the distribution of the SettlementAmount). Your interests will be represented by Lead Plaintiff's Counsel. If you choose, you may enteran appearance individually or through your own counsel at your own expense.

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45. To participate in the distribution of the Settlement Amount, you must timely completeand return the Proof of Claim and Release form.

46. The Proof of Claim and Release must be postmarked on or before , and mailed to the Claims Administrator at the address set forth in 1167.Unless the Court orders otherwise, if you do not timely submit a valid Proof of Claim and Release, youwill be barred from receiving any distribution from the Settlement Amount, but will in all other respectsbe bound by the provisions of the Settlement Stipulation and the Final Judgment.

WHAT RIGHTS AM I GIVING UP BY AGREEING TO THE SETTLEMENT?

47. If the Settlement is approved, the Court will enter the Final Judgment and Order ofDismissal. The Final Judgment will dismiss the claims against the Defendants with prejudice and providethat Lead Plaintiff and all other Class Members shall upon the entry of the Final Judgment be deemed tohave, and by operation of the Final Judgment shall have, fully, finally, and forever released, relinquishedand discharged the Released Persons from all Released Claims (including Unknown Claims).

48. (a) Released Claims are defined as any and all claims, debts, demands, rights, causesof action or liabilities of every nature and description whatsoever (including, but not limited to, claims fordamages, interest, attorneys' fees, expert or consulting fees, and any other costs, expenses, or liabilitywhatsoever), whether based in law or equity, whether fixed or contingent, accrued or unaccrued,liquidated or unliquidated, matured or not matured, pursuant to federal, state, local, statutory or commonlaw, or any other law, rule or regulation, including both known claims and Unknown Claims, that havebeen or could have been asserted in any forum by the Class Members, or any of them, or the successors orassigns of any of them, against any of the Released Persons, which arise out of, are based on, or relate inany way to, directly or indirectly, any of the allegations, acts, transactions, facts, events, matters,occurrences, acts, representations or omissions involved, set forth, alleged or referred to, in the Complaint,or which could have been alleged based upon the facts alleged in the Complaint, and which arise out of,are based upon or are related in any way, directly or indirectly, to the purchase or other acquisitions ofany Sourcefire Common Stock by any Class Member during the Class Period.

(b) Released Persons are defined as each and all of the Defendants, personal or legalrepresentatives of the Defendants, related or affiliated entities of the Defendants (including any SierraVentures related entity or partnership including but not limited to Sierra Ventures V, L.P., Sierra VenturesVI, L.P., Sierra Ventures VII, L.P., Sierra Ventures VIII-A, L.P., Sierra Ventures VIII-B, L.P., SierraVentures IX, L.P., SV Associates V. L.P., SV Associates VI, L.P., Sierra Ventures Associates VII, LLC,Sierra Ventures Associates VIII, LLC, Sierra Ventures Associates IX, LLC, Sierra Ventures FinanceLimited L.P., Sierra Ventures Mauritius, Sierra Ventures Venture Member VIII, LLC, Sierra VenturesVenture Member IX, LLC, Sierra Ventures Venture Member Management VIII, LLC, Sierra VenturesVenture Member Management IX, LLC, Sierra Ventures Management, LLC, Sierra VenturesManagement II, LLC), any entity in which a Defendant has a controlling interest, affiliates, predecessorsin interest, successors in interest, assigns, employees, agents, representatives, attorneys, advisors,accountants, auditors and insurers, co-insurers, re-insurers of the Defendants, the past and present parents,subsidiaries, controlling shareholders, partners, members, principals, divisions, joint ventures, officersand directors of any of the foregoing that is an entity, any spouses or members of the immediate family ofany of the foregoing persons who is a natural person, and the estates, retirement plans, heirs, devisees andlegatees of any of the foregoing persons who is a natural person and any trust of which a Defendant is thesettler of or which is for the benefit of a Defendant's family.

49. Unknown Claims means any and all Released Claims that Lead Plaintiff or any ClassMember does not know or suspect to exist in his, her or its favor at the time of the release of the Released

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Persons. Lead Plaintiff and each Class Member shall have expressly waived any and all provisions, rightsand benefits conferred by any law of any state or territory of the United States, or principle of commonlaw, which is similar, comparable or equivalent to Cal. Civ. Code § 1542, which provides:

A general release does not extend to claims which the creditor does not know orsuspect to exist in his or her favor at the time of executing the release, which ifknown by him or her must have materially affected his or her settlement with thedebtor.

50. Lead Plaintiff and Defendants acknowledge, and the Class Members by operation of lawshall be deemed to have acknowledged, that the inclusion of "Unknown Claims" in the definition ofReleased Claims was separately bargained for and was a key element of the Settlement. Defendants,including any and all of their respective successors in interest, predecessors, representatives, trustees,executors, administrators, heirs, assigns or transferees, immediate and remote, and any person or entityacting for or on behalf of, or claiming under any of them, and each of them, release Plaintiff andPlaintiffs' counsel in the Action from any and all claims arising out of or relating to their filing andprosecution of the Action.

51. If the Settlement is approved, Class Members will release all Released Claims, even ifthey bring, or have brought a lawsuit, arbitration or other proceeding against the Released Personsrelating to the Released Claims. If you have such proceedings, you should consult legal counsel as towhether you should exclude yourself from this Settlement pursuant to the procedures set forth in ¶1152-54below in order to preserve your rights.

IF I DO NOT WANT TO PARTICIPATE IN THESETTLEMENT, HOW DO I EXCLUDE MYSELF?

52. You may request to be excluded from the Class. To do so, you must mail a writtenrequest to the Claims Administrator at: Sourcefire Securities Litigation Exclusions, c/o Complete ClaimSolutions, LLC, P.O. Box 24772, West Palm Beach, FL 33416. The request for exclusion must:(a) state your name, address, and telephone number; (b) provide documentation reflecting all purchases ofSourcefire Common Stock made during the Class Period and sales of Sourcefire Common Stock madefrom March 9, 2007 to July 26, 2007, including the dates, the number of shares, and price paid or receivedper share for each such purchase or sale; and (c) state that you wish to be excluded from the Class. TOBE VALID, A REQUEST FOR EXCLUSION MUST STATE ALL OF THE FOREGOINGINFORMATION. YOUR EXCLUSION REQUEST MUST BE RECEIVED ON OR BEFORE , 2009.

53. If you submit a valid and timely request for exclusion, you shall have no rights under theSettlement, shall not share in the distribution of funds from the Settlement, and shall not be bound by theSettlement Stipulation or the Final Judgment.

54. If you do exclude yourself from the Class, your ability to subsequently initiate a litigation,arbitration or other proceeding against the Defendants concerning the Released Claims may be impactedby the relevant Statute of Limitations. You should consult your own legal counsel concerning this issue.

WHAT PAYMENTS ARE THE ATTORNEYS FOR THE CLASSAND THE LEAD PLAINTIFF SEEKING FOR THEIR WORK IN THIS CASE?

55. Lead Counsel has not received any payment for its services in pursuing this lawsuit onbehalf of the Class, nor have they been reimbursed for their considerable out-of-pocket expenses. Lead

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Counsel intends to apply to the Court for an award of attorneys' fees on behalf of all Plaintiffs' Counselnot to exceed 30% of the Settlement Amount. In addition, Lead Counsel intends to apply forreimbursement of litigation expenses advanced in connection with the Action in an amount not to exceed$100,000. All such fees and expenses will be paid out of the Settlement Amount.

ARE THERE OTHER CONDITIONS THAT MAYAFFECT THE SETTLEMENT OR AN AWARD THEREFROM?

56. The Settlement is conditioned upon the occurrence of certain events. Those eventsinclude, among other things: (a) entry of the Final Judgment by the Court, as provided for in theSettlement Stipulation; and (b) expiration of the time to appeal from the Final Judgment, or if an appeal istaken, a final resolution of the appeal in favor of the Final Judgment. If, for any reason, any one of theconditions described in the Settlement Stipulation is not met, that Settlement Stipulation might beterminated and, if terminated, will become null and void, and the parties to that Settlement Stipulationwill be restored to their respective positions as of the execution of the. Settlement Stipulation.

WHEN AND WHERE WILL THE COURT DECIDE WHETHER TO APPROVETHE SETTLEMENT AND RELATED MATTERS? DO I HAVE TO COME TOTHE HEARING? MAY I SPEAK AT THE HEARING IF I DON'T LIKE THESETTLEMENT OR OTHER MATTERS REFERENCED IN THIS NOTICE?

57. If you do not wish to object to the proposed Settlement, the Plan of Distribution, or theapplication for attorneys' fees and reimbursement of litigation expenses, you need not attend theSettlement Hearing scheduled for , 2009 at •

58. Any member of the Class who has not validly and timely requested to be excluded fromthe Class, and who objects to any aspect of the Settlement, the Plan of Distribution, or the application forattorneys' fees, costs and expenses may appear and be heard at the Settlement Hearing. Any such ClassMember must serve a written notice of objection and any supporting papers by , 2009, upon each of the following: (i) Kaplan Fox & Kilsheimer LLP, RobertN. Kaplan, Esq., Aviah Cohen Pierson, Esq., 850 Third Avenue, New York, NY 10022 (Lead Counsel forLead Plaintiff and the Class); (ii) Hogan & Hartson LLP, Mark Gately, Esq., I 1 1 South Calvert Street,Suite 1600, Baltimore, MD 21202 (on behalf of Defendants); (iii) Cooley Godward Kronish LLP, RobertT. Cahill, Esq., One Freedom Square, Reston Town Center, 119 Freedom Drive, Reston, VA 20190-5656(on behalf of Tim A. Guleri and Sierra Ventures VII, LP); and (iv) DLA Piper LLP (US), David Clarke,Jr., Esq., 500 Eighth Street, NW, Washington, DC 20004 (on behalf of the Underwriter Defendants), andsuch Class Member must file said objections, papers and briefs, showing due proof of service uponcounsel identified above, with the Clerk of the Court, U.S. District Court for the District of Maryland, 101West Lombard Street, Baltimore, MD 21201.

59. The notice of objection must demonstrate the objecting Class Member's membership inthe Class, including documentation reflecting the number of shares of Sourcefire Common Stockpurchased and sold during the Class Period, and must contain a statement of the reasons for objection.Only Class Members who have submitted written notices of objection and related documentation in thismanner will be entitled to be heard at the Settlement Hearing, unless the Court orders otherwise.

60. The Settlement Hearing may be delayed from time to time by the Court without furtherwritten notice to the Class. If you intend to attend the Settlement Hearing, you should confirm the dateand time with Lead Counsel.

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61. Unless otherwise ordered by the Court, any Class Member who does not object in themanner described herein will be deemed to have waived any objection and shall be forever foreclosedfrom making any objection to the proposed Settlement, the application for attorneys' fees andreimbursement of litigation expenses, and/or the proposed Plan of Distribution. Class Members do notneed to appear at the hearing or take any other action to indicate their approval.

WHAT IF I AM A BROKER, BANK OR OTHER NOMINEETHAT BOUGHT SHARES ON SOMEONE ELSE'S BEHALF?

62. If you hold or held any Sourcefire Common Stock purchased during the Class Period asnominee for a beneficial owner, then, within ten (10) days after your receive this Notice, you must either:(a) provide a list of the names and addresses of such beneficial owners to the Claims Administrator,preferably in an MS Excel data table (Please contact the Claims Administrator at 1-800-804-3454 torequest the required file layout for beneficial owners' names and addresses. Alternatively, you mayprovide the Claims Administrator with computer-generated mailing labels (label size Avery 5162);or (b) send a copy of this Notice by first class mail to all such beneficial owners, providing writtenconfirmation to the Claims Administrator of having done so. If you choose to mail the Notice yourself,you may obtain (without cost to you) as many additional copies of this document as you will need tocomplete the mailing by contacting the Claims Administrator as set forth in 67, below.

63. Regardless of whether you choose to complete the mailing yourself or elect to have themailing performed for you, you may obtain reimbursement of reasonable administrative costs actuallyincurred in connection with forwarding the Notice and Proof of Claim and Release and which would nothave been incurred but for the obligation to forward the Notice, after submission to the ClaimsAdministrator of appropriate documentation.

CAN I SEE THE COURT FILE?WHOM SHOULD I CONTACT IF I HAVE QUESTIONS?

64. This Notice is a summary only and does not describe all of the details of the SettlementStipulation. Nothing in this Notice can vary or supersede the terms of the Settlement Stipulation. For fulldetails of the matters discussed in this Notice, you may desire to review the Settlement Stipulation filedwith the Court, which may be inspected during business hours, at the office of the Clerk of the Court,United States Courthouse, United States District Court for the District of Maryland, 101 West LombardStreet, Baltimore, Maryland, 21201.

65. You may also review, at www.completeclaimsolutions.com , the Settlement Stipulation,the Notice, the Proof of Claim and Release, the Order Preliminarily Approving Settlement and Providingfor Notice. These documents will be available on or before , 2009. Thepapers filed in support of the Settlement, and the applications for an award of attorneys' fees andexpenses for Lead Counsel will be available after they are filed with the Court.

66. If you have any questions about the settlement of the Action, you may contact LeadPlaintiff's Counsel by writing. KAPLAN FOX & KILSHETMER LLP, Aviah Cohen Pierson, Esq.,850 Third Avenue, New York, NY 10022.

67. If you need additional copies of this Notice, or if you have a question about filing a claim,you may contact the Claims Administrator at: Sourcefire Securities Litigation, do CompleteClaim Solutions, LLC, P.O. Box 24772, West Palm Beach, FL 33416,wvvw.sourcefiresercuritieslitigation.com , Phone: (800) 804-3454.

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DO NOT TELEPHONE THE COURT REGARDING THIS NOTICE

Dated: , 2009 BY ORDER OF THE COURT

United States District Judge J. Frederick Motz

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EXHIBIT A-2

UNITED STATES DISTRICT COURTDISTRICT OF MARYLAND

(Northern Division)

IN RE SOURCEFIRE, INC. SECURITIES j Master File No. 07-cv-01210-JFMLITIGATION

JUDGE J. FREDERICK MOTZ

EXHIBIT A-2

PROOF OF CLAIM AND RELEASE

I. GENERAL INSTRUCTIONS

A. To recover as a Class Member based upon your claims in this Action, you must completeand, on page 9 hereof, sign this Proof of Claim and Release. If you fail to file a properly addressed Proofof Claim and Release (as set forth below in paragraph C), your claim may be rejected and you may beprecluded from any recovery from the Settlement Fund created in connection with the proposedsettlement of the Litigation.

B. Class Members who do not file acceptable Proofs of Claim and Releases will not share inthe settlement proceeds, but will nevertheless be bound by the Settlement and the judgments of the Court.

C. YOU MUST MAIL YOUR COMPLETED AND SIGNED PROOF OF CLAIM ANDRELEASE POSTMARKED OR RECEIVED ON OR BEFORE ADDRESSED AS FOLLOWS:

Sourcefire Securities Litigationc/o Complete Claim Solutions, LLC

P.O. Box 24772West Palm Beach, FL 33416

YOU WILL BEAR ALL RISKS OF DELAY OR NON-DELIVERY OF YOURCLAIM.

D. If you are NOT a Class Member, as defined in the "Notice of Pendency and ProposedSettlement of Class Action" ("Notice"), DO NOT submit a Proof of Claim and Release.

E. If you are a Class Member, you are bound by the terms of any judgment entered in theLitigation, including the releases provided therein, REGARDLESS OF WHETHER YOU SUBMIT APROOF OF CLAIM AND RELEASE.

II CLAIMANT IDENTIFICATION INSTRUCTIONS

A. If you purchased Sourcefire common stock ("Sourcefire Common Stock") and held thecertificate(s) in your name, you are the beneficial owner as well as the record owner. If, however, youpurchased Sourcefire Common Stock and the certificate(s) were registered in the name of a third party,such as a nominee or brokerage firm, you are the beneficial owner and the third party is the record owner.

B. Use Section IV of this form entitled "Claimant Identification" to identify each owner ofrecord ("nominee"), if different from the beneficial owner of Sourcefire Common Stock which forms thebasis of this claim. THIS CLAIM MUST BE FILED BY THE ACTUAL BENEFICIAL OWNER(S), ORTHE LEGAL REPRESENTATIVE OF SUCH OWNER(S), OF THE SOURCEFIRE COMMONSTOCK UPON WHICH THIS CLAIM IS BASED.

C. All joint owners must sign this claim. Executors, administrators, guardians, conservators,and trustees must complete and sign this claim on behalf of persons represented by them, proof of theirauthority must accompany this claim, and their titles or capacities must be stated.

D. The Social Security or Taxpayer Identification Number and telephone number of thebeneficial owner may be used in verifying the claim. Failure to provide the foregoing information coulddelay verification of your claim and/or result in claim rejection.

HI. TRANSACTION SCHEDULE INSTRUCTIONS

A. Use Section V of this form entitled "Schedule of Transactions in Sourcefire CommonStock" to supply all required details of your transaction(s) in Sourcefire Common Stock. If you need morespace, attach separate, numbered sheets giving all of the required information in substantially the sameformat. Print your name and Social Security or Tax Identification Number at the top of each page.

B. On the schedules, provide all requested information with respect to all of your purchasesof Sourcefire Common Stock that took place at any time beginning March 9, 2007 through April 5, 2007("Class Period") and all of your sales of Sourcefire Common Stock during the period March 9, 2007through July 26, 2007, inclusive whether such transactions resulted in a profit or a loss. Failure to reportall such transactions may result in rejection of your claim.

C. In processing claims, the first-in, first-out ("FIFO") basis will be applied to bothpurchases and sales. List each transaction in the Class Period separately and in chronological order, bytrade date, beginning with the earliest. The date of purchase or sale of Sourcefire Common Stock is the"contract" or "trade" date, as distinguished from the "settlement" date. You must accurately provide themonth, day and year of each transaction you list.

D. The price per share, paid or received, shall be exclusive of all commissions, taxes, feesand other charges.

E. Where Sourcefire Common Stock was purchased or sold by reason of having exercisedan option, the option premium should be incorporated into the price accordingly.

F. All profits will be subtracted from all losses to determine the net Recognized Loss ofeach Claimant.

G. The date of covering a "short sale" is deemed to be the purchase date of SourcefireCommon Stock. The date of a "short sale" is deemed to be the sale date of Sourcefire Common Stock.

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H. No payment will be made on any claim where the potential distribution amount is $10.00or less, but the Claimant will otherwise be bound by the Final Judgment entered by the Court.

I. You must attach to your claim form copies of brokerage confirmations or monthlystatements supporting your trading activity in Sourcefire Common Stock in order for your claim to bevalid. If such documents are not available, a complete list of acceptable supporting documentation can befound on the Claims Administrator's website: wwvv.completeclaimsolutions.com . Failure to provide thisdocumentation could delay verification of your claim and/or result in claim rejection.

J. If your trading activity during the Class Period exceeds 50 transactions, you mustprovide, in an electronic file, all purchases and sales information required in the Schedule of Transactions.For a copy of instructions and parameters concerning such a submission, contact the ClaimsAdministrator by phone: (800) 804-3454.

3

SOURCEFIRE

IN RE SOURCEFIRE, INC. SECURITIES LITIGATION

PROOF OF CLAIM

Must be received by Claims Administrator postmarked no later than

IV. CLAIMANT IDENTIFICATION

Please Type or Print

Beneficial Owner's Name (as it appears on your brokerage statement)

Joint Beneficial Owner's Name (as it appears on your brokerage statement)

Street Address

City State Zip Code

Foreign Province Foreign Country

orSocial Security Number Taxpayer Identification Number

Specify one of the following:o Individual(s) o Corporation o UG1VIA Custodian o IRAo Partnership o Estate o Trust o Other:

(Day) (Evening)Area Code Telephone Number Area Code Telephone Number

Facsimile Number E-Mail Address

Record Owner's Name and Address (if different from beneficial owner listed above)

V. SCHEDULE OF TRANSACTIONS IN SOURCEFIRE COMMON STOCK

A. Separately list each and every purchase of shares of common stock made pursuant to theInitial Public Offering or made during the period March 9, 2007 through April 5, 2007, and provide thefollowing information (must be documented):

Check this boxif transaction is as a result Trade Date(s) of Purchase Number of Amount Paid

of the exercise or (list chronologically) Shares Purchase Price (net of commissions, taxesassignment of an option Month/Day/Year Purchased Per Share & fees)

0

0

B. Separately list each and every sale of shares of common stock during the period March 9,2007 through July 26, 2007, and provide the following information (must be documented):

Check this boxif transaction is as a result Trade Date(s) of Sale Number of Amount Received

of the exercise or (list chronologically) Shares Sale Price (including commissions,assignment of an option Month/Day/Year Sold Per Share taxes & fees)

00

00

C. State the total number of shares of common stock owned at the close of trading onJuly 26, 2007, long or short (must be documented):

If additional space is needed, attach separate, numbered sheets, giving all required information,substantially in the same format, and print your name and Social Security or Taxpayer

Identification Number at the top of each sheet.

YOU MUST ALSO READ AND SIGN THE RELEASE ON PAGE 8.

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VI. SUBMISSION TO JURISDICTION OF COURT AND ACKNOWLEDGMENTS

VWe submit this Proof of Claim and Release under the terms of the Settlement Stipulation, and asdescribed in the Notice. VWe also submit to the jurisdiction of the United States District Court for theDistrict of Maryland with respect to my/our claim as a Class Member and for purposes of enforcing therelease set forth herein. I/We further acknowledge that I am/we are bound by and subject to the terms ofany judgment that may be entered in the Litigation. I/We agree to furnish additional information to LeadPlaintiff's Counsel or the Claims Administrator to support this claim, including details of transactions inother Sourcefire Common Stock, such as options, if requested to do so. 1/We have not submitted anyother claim covering the same purchases or sales of Sourcefire Common Stock during the Class Periodand know of no other person having done so on my/our behalf.

VII. RELEASE

A. I/We hereby acknowledge full and complete satisfaction of, and do hereby fully, finally,and forever settle, release, and discharge from the Released Claims each and all of the Released Persons.

B. "Released Claims" shall mean as any and all claims, debts, demands, rights, causes ofaction or liabilities of every nature and description whatsoever (including, but not limited to, claims fordamages, interest, attorneys' fees, expert or consulting fees, and any other costs, expenses, or liabilitywhatsoever), whether based in law or equity, whether fixed or contingent, accrued or unaccrued,liquidated or unliquidated, matured or not matured, pursuant to federal, state, local, statutory or commonlaw, or any other law, rule or regulation, including both known claims and Unknown Claims, that havebeen or could have been asserted in any forum by the Class Members, or any of them, or the successors orassigns of any of them, against any of the Released Persons, which arise out of, are based on, or relate inany way to, directly or indirectly, any of the allegations, acts, transactions, facts, events, matters,occurrences, acts, representations or omissions involved, set forth, alleged or referred to, in theComplaint, or which could have been alleged based upon the facts alleged in the Complaint, and whicharise out of, are based upon or are related in any way, directly or indirectly, to the purchase or otheracquisitions of any Sourcefire Common Stock by any Class Member during the Class Period.

C. "Unknown Claims" means any and all Released Claims that Lead Plaintiff or any ClassMember does not know or suspect to exist in his, her or its favor at the time of the release of the ReleasedPersons. Lead Plaintiff and each Class Member shall have expressly waived any and all provisions, rightsand benefits conferred by any law of any state or territory of the United States, or principle of commonlaw, which is similar, comparable or equivalent to Cal. Civ. Code § 1542, which provides:

A general release does not extend to claims which the creditor does not know orsuspect to exist in his or her favor at the time of executing the release, which ifknown by him or her must have materially affected his or her settlement with thedebtor.

Lead Plaintiff and Defendants acknowledge, and the Class Members by operation of law shall be deemedto have acknowledged, that the inclusion of "Unknown Claims" in the definition of Released Claims wasseparately bargained for and was a key element of the Settlement. Defendants, including any and all oftheir respective successors in interest, predecessors, representatives, trustees, executors, administrators,heirs, assigns or transferees, immediate and remote, and any person or entity acting for or on behalf of, orclaiming under any of them, and each of them, release Plaintiff and Plaintiffs' counsel in the Action fromany and all claims arising out of or relating to their filing and prosecution of the Action.

6

D. "Released Persons" means each and all of the Defendants, personal or legalrepresentatives of the Defendants, related or affiliated entities of the Defendants (including any SierraVentures related entity or partnership including but not limited to Sierra Ventures V. L.P., Sierra VenturesVI, L.P., Sierra Ventures VII, L.P., Sierra Ventures VIII-A, L.P., Sierra Ventures VIII-B, L.P., SierraVentures IX, L.P., SV Associates V. L.P., SV Associates VI, L.P., Sierra Ventures Associates VII, LLC,Sierra Ventures Associates VIII, LLC, Sierra Ventures Associates IX, LLC, Sierra Ventures FinanceLimited L.P., Sierra Ventures Mauritius, Sierra Ventures Venture Member VIII, LLC, Sierra VenturesVenture Member IX, LLC, Sierra Ventures Venture Member Management VIII, LLC, Sierra VenturesVenture Member Management IX, LLC, Sierra Ventures Management, LLC, Sierra VenturesManagement II, LLC), any entity in which a Defendant has a controlling interest, affiliates, predecessorsin interest, successors in interest, assigns, employees, agents, representatives, attorneys, advisors,accountants, auditors and insurers, co-insurers, re-insurers of the Defendants, the past and present parents,subsidiaries, controlling shareholders, partners, members, principals, divisions, joint ventures, officersand directors of any of the foregoing that is an entity, any spouses or members of the immediate family ofany of the foregoing persons who is a natural person, and the estates, retirement plans, heirs, devisees andlegatees of any of the foregoing persons who is a natural person and any trust of which a Defendant is thesettler of or which is for the benefit of a Defendant's family.

E. This release shall be of no force or effect unless and until the Court approves theSettlement Stipulation and the Settlement becomes effective on the Effective Date (as defined in theSettlement Stipulation).

F. I/We hereby warrant and represent that I/we have not assigned or transferred or purportedto assign or transfer, voluntarily or involuntarily, any matter released pursuant to this release or any otherpart or portion thereof.

G. I/We hereby warrant and represent that I/we have included information about all ofmy/our purchases of Sourcefire Common Stock that occurred during the Class Period, all of my/our salesduring the period March 9, 2007 through July 26, 2007 as well as the amount of Sourcefire CommonStock held by me/us at the close of trading July 26, 2007.

VIII. CERTIFICATION

UNDER THE PENALTY OF PERJURY, I/WE CERTIFY THAT:

I am/we are NOT subject to backup withholding under the provisions of Section 3406(a)(1)(C) ofthe Internal Revenue Code.

NOTE: If you have been notified by the Internal Revenue Service that you are subject tobackup withholding, you must cross out the word "NOT" in the statement above.

I/We declare under penalty of perjury under the laws of the United States of America, that theforegoing information supplied by the undersigned and the supporting documents attached hereto, and theacknowledgments, representations and warranties made herein are true, correct and complete to the best

7

of my/our knowledge, information and belief, and that this Proof of Claim and Release form was executedthis day of , 2009, in

(City) (State/Country)

Signature of Claimant

(Print your name here)

Signature of Joint Claimant, if any

(Print your name here)

Signature of person signing on behalf of Claimant

(Print your name here)

Capacity of person signing on behalf of Claimant, if otherthan an individual (e.g., Executor, President, Custodian, etc.)

ACCURATE CLAIMS PROCESSING TAKES A SIGNIFICANT AMOUNT OF TIME.THANK YOU FOR YOUR PATIENCE.

Reminder Checklist:

1. Please sign the above release and declaration.2. Remember to attach only copies of acceptable supporting documentation, a complete list of which

can be found at the website below.3. Do not send original or copies of stock certificates.4. Keep a copy of the completed claim form and documentation for your records.5. If you desire an acknowledgment of receipt of your claim form, please send it via Certified Mail,

Return Receipt Requested, or its equivalent. You will bear all risks of delay or non-delivery ofyour claim.

6. If your address changes in the future, or if these documents were sent to an old or incorrect address,please send us written notification of your new address.

7. If you have any questions or concerns regarding your claim, please contact the ClaimsAdministrator at:

Sourcefire Securities Litigationc/o Complete Claim Solutions, LLC

P.O. Box 24772West Palm Beach, FL 33416

vvwvv.sourcefiresecuritieslitigation.com

8

EXHIBIT A-3

UNITED STATES DISTRICT COURTDISTRICT OF MARYLAND

(Northern Division)

IN RE SOURCEFIRE, INC. SECURITIES Master File No. 07-cv-01210-JFMLITIGATION

JUDGE J. FREDERICK MOTZ

EXHIBIT A-3

TO ALL PERSONS WHO PURCHASED THE COMMON STOCK OFSOURCEFIRE, INC. DURING THE PERIOD FROM

MARCH 9, 2007 THROUGH APRIL 5, 2007 INCLUSIVE ("CLASS PERIOD")

Please read this notice carefully and in its entirety. Your rights may be affected by the

proceedings described in this notice. A proposed settlement has been reached in this action, as

set forth in a Stipulation of Settlement ("Stipulation"). A hearing will be held with respect to the

proposed settlement on , 2009, at , before the Honorable

J. Frederick Motz, United States District Judge of the District of Maryland, 101 West Lombard

Street, Baltimore, MD 21201.

The purpose of the hearing is to determine whether the proposed settlement with

Defendants Sourcefire, Inc. ("Sourcefire" or the "Company"), E. Wayne Jackson, III,

Thomas M. McDonough, Todd P. Headley, Martin F. Roesch, Asheem Chandna, Tim A. Guleri,

Harry R. Weller, Steven R. Polk, Arnold L. Punaro, Joseph R. Chinnici, Morgan Stanley & Co.

Incorporated, Lehman Brothers Inc., UBS Securities LLC, Jefferies & Company, Inc. and Sierra

Ventures VII, LP (collectively, the "Defendants"), pursuant to which i) $3,200,000 will be paid

in cash into an interest-bearing account maintained on behalf of a class of individuals who

purchased the publicly traded common stock of Sourcefire between March 9, 2007 and April 5,

2007, inclusive, in exchange for a release of claims against the Defendants, should be approved

by the Court as fair, reasonable, adequate and in the best interests of the class. At the hearing,

the Court will also consider the following: a judgment dismissing all claims in the litigation

against the Defendants with prejudice; a plan of distribution; a request by plaintiffs' counsel for

attorneys' fees in an amount up to 30% of the settlement fund and reimbursement of expenses in

an amount not to exceed $100,000; and any other matters that may properly be brought before

the Court in connection with the proposed settlement. If you purchased the common stock of

Sourcefire at any time during the Class Period, you may be entitled to share in the distribution of

the settlement fund by submitting a proof of claim no later than , 2009.

You also have the right to exclude yourself from the proposed settlement or object to the

proposed settlement or the other matters to be considered by the Court at the hearing, in

accordance with the procedures described in a more detailed notice ("Notice") that has been

mailed to members of the Class. If you did not receive a copy of the Notice by mail, you may

obtain a copy and a proof of claim form, or other information by writing to the following

address, calling the following or from the following websites:

Sourcefire Securities Litigationc/o Complete Claim Solutions, LLC

P.O. Box 24772West Palm Beach, FL 33416

Email: info@SourcefireSecuritiesLitigation.comwww.SourcefireSecuritiesLitigation.com

Phone: 800-804-3454

Kaplan Fox & Kilsheimer LLPAviah Cohen Pierson, Esq.

850 Third Avenue, 14th FloorNew York, NY 10022www.kaplanfox.com

Phone: 212-687-1980

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This notice is a summary only and does not describe all of the details of the Stipulation.

Nothing in this notice can vary or supersede the terms of the Stipulation. For full details of the

matters discussed in this notice, you may desire to review the Stipulation filed with the Court, at

the office of the Clerk of the Court, United States Courthouse, United States District Court for

the District of Maryland, 101 West Lombard Street, Baltimore, MD 21201. You may also

review the Stipulation at www.SourcefireSecuritiesLitigation.com or wvvw.kaplanfox.com . This

document is available on both of these websites.

If you are a member of the Class and do not exclude yourself from the Class by

, 2009, or do not submit a proper proof of claim by , 2009, you will not

share in the settlement fund but you will be bound by the Final Judgment of the Court.

Please do not call the Clerk of the Court or Judge Motz for information.

Dated: , 2009 BY ORDER OF THE COURT

United States District Judge J. Frederick Motz

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EXHIBIT B

UNITED STATES DISTRICT COURTDISTRICT OF MARYLAND

(Northern Division)

IN RE SOURCEFIRE, INC. SECURITIES Master File No. 07-cv-01210-JFMLITIGATION

JUDGE J. FREDERICK MOTZ

EXHIBIT B

[PROPOSED] ORDER AND FINAL JUDGMENT

On the day of , 2009, a hearing having been held before

this Court to determine: (1) whether the terms and conditions of the Stipulation and Agreement

of Settlement dated February 10, 2009 (the "Settlement Stipulation") are fair, reasonable and

adequate for the settlement of all claims asserted by the Class against Defendants Sourcefire, Inc.

("Sourcefire" or the "Company"), E. Wayne Jackson, III, Thomas M. McDonough, Todd P.

Headley, Martin F. Roesch , Asheem Chandna, Tim A. Guleri, Harry R. Weller, Steven R. Polk,

Arnold L. Punaro, Joseph R. Chinnici, Morgan Stanley & Co. Incorporated, Lehman Brothers

Inc., UBS Securities LLC, Jefferies & Company, Inc. and Sierra Ventures VII, LP; (2) whether

judgment should be entered dismissing the Complaint, on the merits and with prejudice, in favor

of the Defendants and as against all persons or entities who are members of the Class herein who

have not requested exclusion therefrom; (3) whether to approve the proposed Plan of

Distribution as a fair and reasonable method to allocate the settlement proceeds among Class

Members; and (4) whether and in what amount to award fees and reimbursement of expenses to

Lead Counsel;

The District Court having considered all matters submitted to it at the hearing and

otherwise; and

It appearing that a notice of the Settlement Hearing substantially in the form approved by

the District Court in the Preliminary Order was mailed to all persons and entities reasonably

identifiable who purchased Sourcefire common stock that are the subject of the Action, during

the Class Period; and

It appearing that a summary notice of the Settlement Hearing substantially in the form

approved by the District Court in the Preliminary Order was published in accordance with the

Preliminary Order and the specifications of the Court;

NOW, THEREFORE, IT IS HEREBY ORDERED, ADJUDGED AND DECREED

THAT:

1. The District Court has jurisdiction over the subject matter of the Action, Lead

Plaintiff, all Class Members and the Defendants.

2. All capitalized terms used herein shall have the same meanings as set forth and

defined in the Settlement Stipulation.

3. The District Court finds that the prerequisites for a class action under Rule 23 (a)

and (b)(3) of the Federal Rules of Civil Procedure have been satisfied in that: (a) the number of

members of the Class is so numerous that joinder of all members thereof is impracticable; (b)

there are questions of law and fact common to the Class; (c) the claims of the Lead Plaintiff are

typical of the claims of the Class they seek to represent; (d) Lead Plaintiff fairly and adequately

represents the interests of the Class; (e) the questions of law and fact common to the members of

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the Class predominate over any questions affecting only individual members of the Class; and (f)

a class action is superior to other available methods for the fair and efficient adjudication of the

controversy.

4. Pursuant to Rule 23(a) and (b)(3) of the Federal Rules of Civil Procedure and for

purposes of the Settlement only, the District Court hereby certifies the following action as a class

action: all persons who purchased the publicly traded common stock of Sourcefire during the

period from March 9, 2007 through April 5, 2007, inclusive. Excluded from the Class are any

Released Persons. Class Members are any putative members of the Class who have not excluded

themselves by filing a timely, valid request for exclusion. Those putative members of the Class

who have excluded themselves from the Class by filing a timely, valid request for exclusion are

listed on Exhibit A attached hereto.

5. Pursuant to Rule 23 of the Federal Rules of Civil Procedure, and for purposes of

the Settlement only, Lead Plaintiff is certified as class representative and the Lead Counsel

previously selected by Lead Plaintiff and appointed by the District Court is hereby appointed as

Lead Counsel for the Class.

6. The Settlement Stipulation is approved as fair, reasonable and adequate, and in

the best interests of the Class. Lead Plaintiff and the Defendants are directed to consummate the

Settlement in accordance with the terms and provisions of the Settlement Stipulation.

7. The Action is hereby dismissed with prejudice and without costs.

8. Lead Plaintiff and the Class Members hereby release and forever discharge each

and all of the Defendants, personal or legal representatives of the Defendants, related or affiliated

entities of the Defendants (including any Sierra Ventures related entity or partnership including

but not limited to Sierra Ventures V, L.P., Sierra Ventures VI, L.P., Sierra Ventures VII, L.P.,

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Sierra Ventures VIII-A, L.P., Sierra Ventures VIII-B, L.P., Sierra Ventures IX, L.P., SV

Associates V, L.P., SV Associates VI, L.P., Sierra Ventures Associates VII, LLC, Sierra

Ventures Associates VIII, LLC, Sierra Ventures Associates IX, LLC, Sierra Ventures Finance

Limited L.P., Sierra Ventures Mauritius, Sierra Ventures Venture Member VIII, LLC, Sierra

Ventures Venture Member IX, LLC, Sierra Ventures Venture Member Management VIII, LLC,

Sierra Ventures Venture Member Management IX, LLC, Sierra Ventures Management, LLC,

Sierra Ventures Management II, LLC), any entity in which a Defendant has a controlling interest,

affiliates, predecessors in interest, successors in interest, assigns, employees, agents,

representatives, attorneys, advisors, accountants, auditors and insurers, co-insurers, re-insurers of

the Defendants, the past and present parents, subsidiaries, controlling shareholders, partners,

members, principals, divisions, joint ventures, officers and directors of any of the foregoing that

is an entity, any spouses or members of the immediate family of any of the foregoing persons

who is a natural person, and the estates, retirement plans, heirs, devisees and legatees of any of

the foregoing persons who is a natural person and any trust of which a Defendant is the settler of

or which is for the benefit of a Defendant's family (collectively, the "Released Persons"), from

any and all claims, debts, demands, rights, causes of action or liabilities of every nature and

description whatsoever (including, but not limited to, claims for damages, interest, attorneys'

fees, expert or consulting fees, and any other costs, expenses, or liability whatsoever), whether

based in law or equity, whether fixed or contingent, accrued or unaccrued, liquidated or

unliquidated, matured or not matured, pursuant to federal, state, local, statutory or common law,

or any other law, rule or regulation, including both known claims and Unknown Claims, that

have been or could have been asserted in any forum by the Class Members, or any of them, or

the successors or assigns of any of them, against any of the Released Persons, which arise out of,

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are based on, or relate in any way to, directly or indirectly, any of the allegations, acts,

transactions, facts, events, matters, occurrences, acts, representations or omissions involved, set

forth, alleged or referred to, in the Complaint, or which could have been alleged based upon the

facts alleged in the Complaint, and which arise out of, are based upon or are related in any way,

directly or indirectly, to the purchase or other acquisitions of any Sourcefire common stock by

any Class Member during the Class Period.

9. Lead Plaintiff and the Class Members are hereby permanently barred and

enjoined from prosecuting the Released Claims against the Released Persons.

10. Upon the Effective Date of the Settlement, all claims for contribution,

indemnification, or any other form of relief by other alleged joint tortfeasors against the Released

Persons based upon, arising out of, relating to, or in connection with the Released Claims of the

Class or any Class Member are hereby barred, extinguished, discharged, satisfied and otherwise

rendered unenforceable to the full extent permitted by law, and the future filing of any such

claims enjoined. Nothing in this Order and Final Judgment shall be deemed to release, impair or

affect the indemnity rights of any Released Person.

11. The District Court finds that all parties and their counsel have complied with each

requirement of Rule 11 of the Federal Rules of Civil Procedure as to all proceedings herein.

12. Neither this Order and Final Judgment, the Settlement Stipulation, nor any of the

negotiations, documents or proceedings connected with them shall be:

(a) referred or used against the Released Persons or against the Class as

evidence of wrongdoing by anyone;

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(b) construed against the Released Persons or the Class as an admission or

concession that the consideration to be given hereunder represents the

amount which could be or would have been recovered after trial; or

(c) construed as, or received in evidence as, an admission, concession or

presumption against the Class or any of them, that any of their claims are

without merit or that damages recoverable under the Complaint would not

have exceeded the Settlement Fund.

13. Exclusive jurisdiction is hereby retained over the parties and the Class Members

for all matters relating to the Action, including the administration, interpretation, effectuation or

enforcement of the Settlement Stipulation and this Order and Final Judgment, and including any

application for fees and expenses incurred in connection with administering and distributing the

settlement proceeds to the Class Members.

14. Without further order of the District Court, the parties may agree to reasonable

extensions of time to carry out any of the provisions of the Settlement Stipulation.

15. The finality of this Order and Final Judgment shall not be affected, in any manner,

by rulings that the District Court may make on the Lead Counsel's application for an award of

attorneys' fees and reimbursement of expenses.

16. The District Court hereby finds that the notice provided to the Class provided the

best notice practicable under the circumstances. Said notice provided due and adequate notice of

these proceedings and the matters set forth herein, including the Settlement and Plan of

Distribution, to all persons entitled to such notice, and said notice fully satisfied the requirements

of Rule 23 of the Federal Rules of Civil Procedure and the requirements of due process. A full

opportunity has been offered to the Class Members to object to the proposed Settlement and to

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participate in the hearing thereon. Thus, it is hereby determined that all members of the Class

are bound by this Order and Final Judgment except those persons set forth on Exhibit A.

17. In the event that the Settlement does not become final and effective in accordance

with the terms and conditions set forth in the Settlement Stipulation, then this Order and Final

Judgment shall be rendered null and void and be vacated and the Settlement and all orders

entered in connection therewith shall be rendered null and void (except as provided in n 6-8, 27,

28, 32, 33 and 44 in the Settlement Stipulation), and the parties shall be returned to their

respective positions immediately prior to the execution of the Settlement Stipulation.

Dated: Baltimore, Maryland , 2009

United States District Judge J. Frederick Motz

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