Windows: Detect baaupdate.exe Spawning Scripting, Admin, or LOLBin Child Processes

Alerts when baaupdate.exe runs typical script/utility processes, an uncommon parent-child execution pattern on Windows.

FreeReviewedSigma · High · v2

Product: windows
Category: process_creation
Author: andrewdanis, Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2025-10-18
Updated: 2026-07-31

ATT&CK techniques

Defense Evasion → Lateral Movement

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1218System Binary Proxy Execution
Cred Access
Discovery
Lateral Movement
- T1021.003Distributed Component Object Model
Collection
C2
Exfiltration
Impact

What it detects

This rule flags executions where baaupdate.exe launches specific child processes, including bitsadmin.exe, cmd.exe, cscript.exe, mshta.exe, powershell.exe/ISE, regsvr32.exe, rundll32.exe, schtasks.exe, wmic.exe, and wscript.exe. Using baaupdate.exe as the parent for these utilities can indicate an attempt to run additional code or scripts in the context of BitLocker-related update tooling. The detection relies on Windows process creation telemetry, matching parent and child process image paths by filename.

Reporting behind it

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Windows: Detect baaupdate.exe Spawning Scripting, Admin, or LOLBin Child Processes

Pivot detection · T1218 · 9 related

Changelog

v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

windows-baaupdate-exe-spawns-suspicious-utilities-9f38c1db

title: "Windows: Detect baaupdate.exe Spawning Scripting, Admin, or LOLBin Child Processes"
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 executions where baaupdate.exe launches specific child processes, including bitsadmin.exe, cmd.exe, cscript.exe, mshta.exe, powershell.exe/ISE, regsvr32.exe, rundll32.exe, schtasks.exe, wmic.exe, and wscript.exe. Using baaupdate.exe as the parent for these utilities can indicate an attempt to run additional code or scripts in the context of BitLocker-related update tooling. The detection relies on Windows process creation telemetry, matching parent and child process image paths by filename.
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

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This rule as a query you can run. Uses no unlock credit.

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