Posts Tagged ‘ntlm’

The hijacking of port 445 to perform relay attacks or hash capturing attacks has been a recurring topic for a while now. When you infect a target with meterpreter, how do you listen on port 445? A few weeks ago this topic resurfaced again in part due to Dirk-jan (@_dirkjan) that saw this question flying by in the #bloodhoundgang slack channel and asked me to look into it. This sounded like fun to figure out and he promised that if it worked, he’d document a working setup that would be able to perform SMB relay attacks through meterpreter. Turns out, this is an already solved problem with readily available tools out there, but not a lot of people are aware about the solution.

We will explain how you can leverage these tools to perform relay attacks on a target on which you have a meterpreter session. The added benefit of this approach is the fact that you don’t need python2exe or a whole python stack on the infected host, just a simple driver and a meterpreter infection will do the trick.

The first part of this blog will focus on the thought process of being able to hijack port 445 and the second part of this entry will focus on making it usable for relay attacks. If you want to skip the thought process and relay setup you can also skip directly to the already available solution:

The rest of this entry is divided into the following sections:

  • Who is the owner of port 445?
  • Hijacking and redirecting port 445
  • The full SMB relay setup through meterpreter

Please note that we took the easy route while writing this blog post and just put all the files on the disk. If you want to avoid that we suggest that you use a ram disk solution or expand the current meterpreter in-memory execution functionality to support something similar to this.

In addition there is a high probability that you either have to recompile the source of the solution statically to ensure you won’t be needing additional DDL files or you’ll have to bundle those DLL files. All this is however left as an exercise to the reader ;)
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