Install OpenSSH for Windows - Metasploit


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

Table Of Contents
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Module Overview

Name: Install OpenSSH for Windows
Module: post/windows/manage/install_ssh
Source code: modules/post/windows/manage/install_ssh.rb
Disclosure date: -
Last modification time: 2020-01-19 19:51:44 +0000
Supported architecture(s): x86, x64
Supported platform(s): Windows
Target service / protocol: -
Target network port(s): -
List of CVEs: -

This module installs OpenSSH server and client for Windows using PowerShell. SSH on Windows can provide pentesters persistent access to a secure interactive terminal, interactive filesystem access, and port forwarding over SSH.

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/manage/install_ssh

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/manage/install_ssh
msf post(install_ssh) > show options
    ... show and set options ...
msf post(install_ssh) > set SESSION session-id
msf post(install_ssh) > 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/manage/install_ssh")
  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.

Knowledge Base

Creating A Testing Environment

To use this module you need an administrative Meterpreter or shell session on a Windows 10, 1809 release or higher.

This module has been tested against:

  1. Windows 10, 1903.

This module was not tested against, but may work against:

  1. Windows 10, 1809 and above.

Versions prior to Windows 10 are not supported.

Module Options

  • INSTALL_SERVER - Install OpenSSH.Server for Windows (default: true)
  • INSTALL_CLIENT - Install OpenSSH.Client for Windows (default: true)
  • UNINSTALL_SERVER - Uninstall OpenSSH.Server for Windows (default: false)
  • UNINSTALL_CLIENT - Uninstall OpenSSH.Client for Windows (default: false)
  • SERVER_VER - OpenSSH.Server version (default "OpenSSH.Server~~~~0.0.1.0")
  • CLIENT_VER - OpenSSH.Client version (default "OpenSSH.Client~~~~0.0.1.0")
  • AUTOSTART - Sets sshd service to startup automatically at system boot for persistence (default: true)

Verification Steps

  1. Start msfconsole
  2. Obtain a meterpreter or shell session
  3. Do: use post/windows/manage/install_ssh
  4. Do: set session #
  5. Do: run
  6. Open a new terminal and test SSH access: ssh [email protected]

Scenarios

Install OpenSSH on Windows

  msf5 > use post/windows/manage/install_ssh 
  msf5 post(windows/manage/install_ssh) > set SESSION 1 
  SESSION => 1
  msf5 post(windows/manage/install_ssh) > exploit 

  [*] Installing OpenSSH.Server
  [*] Installing OpenSSH.Client
  [*] Post module execution completed

Utilities such as ssh, sftp, and sshfs may be used over the Windows SSH session. When combined with capabilities such as SSH forwarding, SSH on Windows can provide pentesters excellent utility and flexibility.

Uninstall OpenSSH on Windows

  msf5 > use post/windows/manage/install_ssh 
  msf5 post(windows/manage/install_ssh) > set SESSION 1 
  SESSION => 1
  msf5 post(windows/manage/install_ssh) > set INSTALL_CLIENT false 
  INSTALL_CLIENT => false
  msf5 post(windows/manage/install_ssh) > set INSTALL_SERVER false 
  INSTALL_SERVER => false
  msf5 post(windows/manage/install_ssh) > set UNINSTALL_CLIENT true 
  UNINSTALL_CLIENT => true
  msf5 post(windows/manage/install_ssh) > set UNINSTALL_SERVER true 
  UNINSTALL_SERVER => true
  msf5 post(windows/manage/install_ssh) > exploit 

  [*] Uninstalling OpenSSH.Server
  [*] Uninstalling OpenSSH.Client
  [*] Post module execution completed

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Msfconsole Usage

Here is how the windows/manage/install_ssh post exploitation module looks in the msfconsole:

msf6 > use post/windows/manage/install_ssh

msf6 post(windows/manage/install_ssh) > show info

       Name: Install OpenSSH for Windows
     Module: post/windows/manage/install_ssh
   Platform: Windows
       Arch: x86, x64
       Rank: Normal

Provided by:
  Michael Long <[email protected]>

Compatible session types:
  Meterpreter
  Shell

Basic options:
  Name              Current Setting            Required  Description
  ----              ---------------            --------  -----------
  AUTOSTART         true                       yes       Sets sshd service to startup automatically at system boot for persistence
  CLIENT_VER        OpenSSH.Client~~~~0.0.1.0  yes       OpenSSH.Client version
  INSTALL_CLIENT    true                       yes       Install OpenSSH.Client for Windows
  INSTALL_SERVER    true                       yes       Install OpenSSH.Server for Windows
  SERVER_VER        OpenSSH.Server~~~~0.0.1.0  yes       OpenSSH.Server version
  SESSION                                      yes       The session to run this module on.
  UNINSTALL_CLIENT  false                      yes       Uninstall OpenSSH.Client for Windows
  UNINSTALL_SERVER  false                      yes       Uninstall OpenSSH.Server for Windows

Description:
  This module installs OpenSSH server and client for Windows using 
  PowerShell. SSH on Windows can provide pentesters persistent access 
  to a secure interactive terminal, interactive filesystem access, and 
  port forwarding over SSH.

References:
  https://docs.microsoft.com/en-us/windows-server/administration/openssh/openssh_overview
  https://github.com/PowerShell/openssh-portable

Module Options

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

msf6 post(windows/manage/install_ssh) > show options

Module options (post/windows/manage/install_ssh):

   Name              Current Setting            Required  Description
   ----              ---------------            --------  -----------
   AUTOSTART         true                       yes       Sets sshd service to startup automatically at system boot for persistence
   CLIENT_VER        OpenSSH.Client~~~~0.0.1.0  yes       OpenSSH.Client version
   INSTALL_CLIENT    true                       yes       Install OpenSSH.Client for Windows
   INSTALL_SERVER    true                       yes       Install OpenSSH.Server for Windows
   SERVER_VER        OpenSSH.Server~~~~0.0.1.0  yes       OpenSSH.Server version
   SESSION                                      yes       The session to run this module on.
   UNINSTALL_CLIENT  false                      yes       Uninstall OpenSSH.Client for Windows
   UNINSTALL_SERVER  false                      yes       Uninstall OpenSSH.Server for Windows

Advanced Options

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

msf6 post(windows/manage/install_ssh) > show advanced

Module advanced options (post/windows/manage/install_ssh):

   Name                                    Current Setting  Required  Description
   ----                                    ---------------  --------  -----------
   Powershell::Post::dry_run               false            yes       Return encoded output to caller
   Powershell::Post::force_wow64           false            yes       Force WOW64 execution
   Powershell::Post::log_output            false            yes       Write output to log file
   Powershell::Post::timeout               15               yes       Powershell execution timeout, set < 0 to run async without termination
   Powershell::encode_final_payload        false            yes       Encode final payload for -EncodedCommand
   Powershell::encode_inner_payload        false            yes       Encode inner payload for -EncodedCommand
   Powershell::exec_in_place               false            yes       Produce PSH without executable wrapper
   Powershell::exec_rc4                    false            yes       Encrypt PSH with RC4
   Powershell::method                      reflection       yes       Payload delivery method (Accepted: net, reflection, old, msil)
   Powershell::no_equals                   false            yes       Pad base64 until no "=" remains
   Powershell::noninteractive              true             yes       Execute powershell without interaction
   Powershell::persist                     false            yes       Run the payload in a loop
   Powershell::prepend_protections_bypass  true             yes       Prepend AMSI/SBL bypass
   Powershell::prepend_sleep                                no        Prepend seconds of sleep
   Powershell::remove_comspec              false            yes       Produce script calling powershell directly
   Powershell::strip_comments              true             yes       Strip comments
   Powershell::strip_whitespace            false            yes       Strip whitespace
   Powershell::sub_funcs                   false            yes       Substitute function names
   Powershell::sub_vars                    true             yes       Substitute variable names
   Powershell::wrap_double_quotes          true             yes       Wraps the -Command argument in single quotes
   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/manage/install_ssh module can do:

msf6 post(windows/manage/install_ssh) > show actions

Post actions:

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

Evasion Options

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

msf6 post(windows/manage/install_ssh) > 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.

Insufficient privileges to install or remove OpenSSH

Here is a relevant code snippet related to the "Insufficient privileges to install or remove OpenSSH" error message:

38:	  end
39:	
40:	  def run
41:	    # check admin privileges
42:	    unless is_system? || is_admin?
43:	      fail_with(Failure::NotVulnerable, "Insufficient privileges to install or remove OpenSSH")
44:	    end
45:	
46:	    # check if PowerShell is available
47:	    psh_path = "\\WindowsPowerShell\\v1.0\\powershell.exe"
48:	    if !file? "%WINDIR%\\System32#{psh_path}"

No powershell available.

Here is a relevant code snippet related to the "No powershell available." error message:

44:	    end
45:	
46:	    # check if PowerShell is available
47:	    psh_path = "\\WindowsPowerShell\\v1.0\\powershell.exe"
48:	    if !file? "%WINDIR%\\System32#{psh_path}"
49:	      fail_with(Failure::NotVulnerable, "No powershell available.")
50:	    end
51:	
52:	    # uninstall OpenSSH.Server
53:	    if datastore['UNINSTALL_SERVER']
54:	      print_status("Uninstalling OpenSSH.Server")

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References

See Also

Check also the following modules related to this module:

Authors

  • Michael Long <bluesentinel[at]protonmail.com>

Version

This page has been produced using Metasploit Framework version 6.1.24-dev. For more modules, visit the Metasploit Module Library.

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