Metasploit Unleashed : Hacking Remote Systems With Ease

The Metasploit Project is an open-source, computer security project which provides information about security vulnerabilities and aids in penetration testing and IDS signature development.
Its most well-known sub-project is the Metasploit Framework, a tool for developing and executing exploit code against a remote target machine. Other important sub-projects include the Opcode Database, shellcode archive, and security research.
The Metasploit Project is also well known for anti-forensic and evasion tools, some of which are built into the Metasploit Framework.

The basic steps for exploiting a system using the Framework include -

1. Choosing and configuring an exploit (code that enters a target system by taking advantage of one of its bugs; about 300 different exploits for Windows, Unix/Linux and Mac OS X systems are included);
   
2. Checking whether the intended target system is susceptible to the chosen exploit (optional);
   
3. Choosing and configuring a payload (code that will be executed on the target system upon successful entry; for instance, a remote shell or a VNC server);
4. Choosing the encoding technique to encode the payload so that the intrusion-prevention system (IPS) will not catch the encoded payload;
   
5. Executing the exploit.

This modularity of allowing to combine any exploit with any payload is the major advantage of the Framework: it facilitates the tasks of attackers, exploit writers, and payload writers.

Versions of the Metasploit Framework since v3.0 are written in the Ruby programming language. The previous version, 2.8, was implemented in Perl. It runs on all versions of Unix (including Linux and Mac OS X), and also on Windows. It includes two command-line interfaces, a web-based interface and a native GUI. The web interface is intended to be run from the attacker's computer. The Metasploit Framework can be extended to use external add-ons in multiple languages.

To choose an exploit and payload, some information about the target system is needed such as operating system version and installed network services. This information can be gleaned with port scanning and OS fingerprinting tools such as nmap. Vulnerability scanners such as NeXpose or Nessus can detect the target system vulnerabilities. Metasploit can import vulnerability scan data and compare the identified vulnerabilities to existing exploit modules for accurate exploitation.

Courtesy : http://en.wikipedia.org/wiki/Metasploit_Project

Official Metsploit Unleashed Tutorial link : http://www.offensive-security.com/metasploit-unleashed/Main_Page