Windows Security Log: Network Write of wbemcomn.dll in System32\wbem for WMI DLL Hijack (T1047)

Flags remote creation of wbemcomn.dll in System32\wbem associated with WMI DLL hijack activity.

FreeReviewedSigma · High · v2
Product
windows
Service
security
Author
Roberto Rodriguez @Cyb3rWard0g, Open Threat Research (OTR) (SigmaHQ), DRL 1.1
Published
2020-10-12
Updated
2026-07-31
title: "Windows Security Log: Network Write of wbemcomn.dll in System32\\wbem for WMI DLL Hijack (T1047)"
id: 4d825f30-f26d-445f-8427-f45603387c3c
status: test
description: This rule flags creation of a file named wbemcomn.dll within C:\Windows\System32\wbem\ when the file operation is sourced over the network (EventID 5145). Attackers may use this placement to enable WMI DLL Hijacking via DLL search order or hijacking patterns. The detection relies on Windows Security auditing for network file access and specifically matches the target filename ending with \wbem\wbemcomn.dll while excluding machine accounts ending with '$'.
references:
  - https://threathunterplaybook.com/hunts/windows/201009-RemoteWMIWbemcomnDLLHijack/notebook.html
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/builtin/security/win_security_wmiprvse_wbemcomn_dll_hijack.yml
author: Roberto Rodriguez @Cyb3rWard0g, Open Threat Research (OTR), Huntrule Team
date: 2020-10-12
modified: 2022-02-24
tags:
  - attack.execution
  - attack.t1047
  - attack.lateral-movement
  - attack.t1021.002
logsource:
  product: windows
  service: security
detection:
  selection:
    EventID: 5145
    RelativeTargetName|endswith: \wbem\wbemcomn.dll
  filter:
    SubjectUserName|endswith: $
  condition: selection and not filter
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: f6c68d5f-e101-4b86-8c84-7d96851fd65c
    type: derived