Hacker, Cracker?!

Are they the same?

No!!!

Hacker

programmers intensely interested in the arcane and recondite

workings of any computer operating system. advanced knowledge of operating systems and

programming languages.– know of holes within systems and the reasons for such holes.

Hackers constantly seek further knowledge, freely share what they have discovered, and never, ever intentionally damage data.

Cracker

breaks into or otherwise violates the system integrity of remote machines, with malicious intent.

having gained unauthorized access, destroy vital data, deny legitimate users service, or basically cause problems for their targets.

can easily be identified because their actions are malicious.

Tools for hacking

Scanners

Trojan Horses

Packet sniffing

Password Cracker

Scanners

In Internet security, no hacking tool is more celebrated than the scanner.

good TCP port scanner is worth a thousand user passwords.

What Is a Scanner?

program – automatically detects security weaknesses in a

remote or local host.

important to Internet security – reveal weaknesses in the network

How Do Scanners Work?

Every PC has 65535 port TCP port scanners programs which

– attack TCP/IP ports and services (Telnet or FTP, for example) and record the response from the target.

– glean valuable information about the target host

What Will a Scanner Tell Me?

reveal certain inherent weaknesses within the target host. – These might be key factors in implementing an

actual compromise of the target's security.

What Won't a Scanner Tell Me?

A step-by-step method of breaking in

The degree to which your scanning activity has been logged

Password Cracker

Program – can decrypt passwords or otherwise disable

password protection.– Most of them need not decrypt anything.Real

encrypted passwords cannot be reverse-decrypted.

Packet sniffing

program captures data from information packets as they travel over the network. data may include

user names, passwords, and proprietary information that travels over the network in clear text.

With perhaps hundreds or thousands of passwords captured by the packet sniffer, intruders can launch widespread attacks on systems.

Installing a packet sniffer does not necessarily require administrator-level access.

Trojan horse

program – containing hidden functions

can exploit the privileges of the user [running the program], with a resulting security threat.

– does things that the program user did not intend rely on users to install them can be installed by intruders who have gained

unauthorized access by other means.

What do Trojan horses do?

can do anything that the user executing the program has the privileges to do.Include: – deleting files that the user can delete – transmitting to the intruder any files that the user

can read – changing any files the user can modify installing

viruses – installing other Trojan horses

– installing other programs with the privileges of the user

programs that provide unauthorized network access

– executing privilege-elevation attacks

Example of Trojans

Back Orifice NetBus

The most common attack

DDoS

DDoS

DDoS(distributed denial-of-service) DoS

– is called a attack(denial-of-service DoS) causes your computer to crash or to become so busy

processing data that you are unable to use it

Ping of Death

Sending too large ping request. Fragmentation allow to send this large packet.

– When packet re-combine,this will overload the buffer.

SYN Flooding

Send tons of SYN(SYNchronize) request to server When server send SYN-ACK(ACKnowledge) response,

it can’t send the last acknowledgment request. Result- use up the network buffer.

Contributes of hacker??

Linux is written by hacker!!

The End