Detection rules › Sigma
Suspicious BitLocker Access Agent Update Utility Execution
Detects the execution of the BitLocker Access Agent Update Utility (baaupdate.exe) which is not a common parent process for other processes. Suspicious child processes spawned by baaupdate.exe could indicate an attempt at lateral movement via BitLocker DCOM & COM Hijacking.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Stealth | T1218 System Binary Proxy Execution |
| Lateral Movement | T1021.003 Remote Services: Distributed Component Object Model |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
Rule body yaml
title: Suspicious BitLocker Access Agent Update Utility Execution
id: 9f38c1db-e2ae-40bf-81d0-5b68f73fb512
related:
- id: 6e8fe0a8-ba0b-4a93-8f9e-82657e7a5984 # BaaUpdate.exe Suspicious DLL Load
type: similar
status: experimental
description: |
Detects the execution of the BitLocker Access Agent Update Utility (baaupdate.exe) which is not a common parent process for other processes.
Suspicious child processes spawned by baaupdate.exe could indicate an attempt at lateral movement via BitLocker DCOM & COM Hijacking.
references:
- https://github.com/rtecCyberSec/BitlockMove
author: andrewdanis, Swachchhanda Shrawan Poudel (Nextron Systems)
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
Stages and Predicates
Stage 0: condition
selectionStage 1: selection
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'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Image | ends_with |
|
ParentImage | ends_with |
|