Windows: baaupdate.exe Spawns Suspicious Utilities

title: "Windows: baaupdate.exe Spawns Suspicious Utilities"
id: ca8919cd-a4b6-4209-b65e-7954dad4e637
related:
  - id: 6e8fe0a8-ba0b-4a93-8f9e-82657e7a5984
    type: similar
  - id: 9f38c1db-e2ae-40bf-81d0-5b68f73fb512
    type: derived
status: experimental
description: This rule flags process creation where BitLocker Access Agent Update Utility (baaupdate.exe) launches a child process matching common script, command, and utility executables. Attackers may abuse this unusual parent/child relationship to execute additional commands or payloads, potentially supporting stealthy execution paths. It relies on Windows process creation telemetry including the parent image and the spawned child image.
references:
  - https://github.com/rtecCyberSec/BitlockMove
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_baaupdate_susp_child_process.yml
author: andrewdanis, Swachchhanda Shrawan Poudel (Nextron Systems), Huntrule Team
date: 2025-10-18
tags:
  - attack.stealth
  - attack.t1218
  - attack.lateral-movement
  - attack.t1021.003
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    ParentImage|endswith: \baaupdate.exe
    Image|endswith:
      - \bitsadmin.exe
      - \cmd.exe
      - \cscript.exe
      - \mshta.exe
      - \powershell_ise.exe
      - \powershell.exe
      - \regsvr32.exe
      - \rundll32.exe
      - \schtasks.exe
      - \wmic.exe
      - \wscript.exe
  condition: selection
falsepositives:
  - Unknown
level: high
license: DRL-1.1