.. /Runexehelper.exe

Star

Paths:

• c:\windows\system32\runexehelper.exe

Resources:

• https://twitter.com/0gtweet/status/1206692239839289344

Acknowledgements:

• Grzegorz Tworek (@0gtweet)

Detections:

• Sigma: https://github.com/SigmaHQ/sigma/blob/197615345b927682ab7ad7fa3c5f5bb2ed911eed/rules/windows/process_creation/proc_creation_win_lolbin_runexehelper.yml
• IOC: c:\windows\system32\runexehelper.exe is run
• IOC: Existence of runexewithargs_output.txt file

Execute

1. Launches the specified exe. Prerequisites: (1) diagtrack_action_output environment variable must be set to an existing, writable folder; (2) runexewithargs_output.txt file cannot exist in the folder indicated by the variable.

   runexehelper.exe c:\windows\system32\calc.exe

   Use case

   Executes arbitrary code

   Privileges required

   User

   Operating systems

   Windows 10, Windows 11, Windows Server 2012, Windows Server 2016, Windows Server 2019, Windows Server 2022

   ATT&CK® technique

   T1218