Windows: Alert on Unusual Child Process of Setres.EXE Spawning 'choice' Executables

title: "Windows: Alert on Unusual Child Process of Setres.EXE Spawning 'choice' Executables"
id: 72025854-d9bc-450e-847f-cfb149aa9223
status: test
description: This rule flags process creation events where a child process contains the substring "\choice" and the parent process is setres.exe. Setres.exe is a Windows server-only utility used to change screen resolution, so unexpected children can indicate misuse to launch attacker-controlled content. The detection relies on process creation telemetry, specifically the parent image path and the child image path contents, and excludes known legitimate choice.exe locations under System32 and SysWOW64.
references:
  - https://lolbas-project.github.io/lolbas/Binaries/Setres/
  - https://twitter.com/0gtweet/status/1583356502340870144
  - https://strontic.github.io/xcyclopedia/library/setres.exe-0E30E4C09637D7A128A37B59A3BC4D09.html
  - https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc731033(v=ws.11)
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_setres_uncommon_child_process.yml
author: "@gott_cyber, Nasreddine Bencherchali (Nextron Systems), Huntrule Team"
date: 2022-12-11
modified: 2024-06-26
tags:
  - attack.stealth
  - attack.t1218
  - attack.t1202
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    ParentImage|endswith: \setres.exe
    Image|contains: \choice
  filter_main_legit_location:
    Image|endswith:
      - C:\Windows\System32\choice.exe
      - C:\Windows\SysWOW64\choice.exe
  condition: selection and not 1 of filter_main_*
falsepositives:
  - Unlikely
level: high
license: DRL-1.1
related:
  - id: 835e75bf-4bfd-47a4-b8a6-b766cac8bcb7
    type: derived