making your own payload

[mmiller at hick.org (mmiller at hick.org)]

On Tue, Dec 06, 2005 at 04:24:04PM +0000, pagvac wrote:
> I have an executable file which I would like to convert into a
> payload. That way I could use it with all the exploits that metasploit
> supports.
>
> This executable automates many tasks that I usually do on the target
> machines after comprising them when doing penetration testing.
>
> The problem is that I have no idea on how to remove all the nulls
> (0x00) so that the exploit doesn't break.
>
> I'd like to have some references on documentation/tools that can help
> me create this payload and successfully run it with metasploit on
> existing exploit modules.
>
> Question: are all payloads compatible with metasploit? In other words,
> can I get a shellcode from an external resource and use it
> successfully with metasploit?

Converting an executable into shellcode is typically infeasible due to
the nature in which most executables are compiled.  One of the
constraints also becomes the size of the shellcode produced and the
manner in which it is to be transferred to the target.  Is there a
reason that you can't use the upexec payloads (upload and execute)?

win32_xxx_upexec