Windows: Detect Suspicious mofcomp.exe Execution from Scripts or Temp Paths
Flags mofcomp.exe runs spawned by script interpreters or using temp/AppData paths, with exclusions for WmiPrvSE .mof-related activity.
- Product
- windows
- Category
- process_creation
- Author
- Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
- Published
- 2022-07-12
- Updated
- 2026-07-30
ATT&CK techniques
Defense EvasionRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule identifies execution of mofcomp.exe when it is launched as a child of common scripting shells (cmd.exe, PowerShell, pwsh, wsl.exe, wscript.exe, cscript.exe) or when the command line includes suspicious TEMP/AppData locations. It focuses on cases where mofcomp may be used to import attacker-controlled MOF content into the WMI repository. The detection relies on Windows process creation telemetry fields for process image names, parent image paths, and command-line content, and it excludes likely benign invocations tied to WmiPrvSE.exe with specific .mof handling in C:\Windows\TEMP.
Reporting behind it
- thedfirreport.comhttps://thedfirreport.com/2022/07/11/select-xmrig-from-sqlserver/
- github.comhttps://github.com/The-DFIR-Report/Sigma-Rules/blob/75260568a7ffe61b2458ca05f6f25914efb44337/win_mofcomp_execution.yml
- learn.microsoft.comhttps://learn.microsoft.com/en-us/windows/win32/wmisdk/mofcomp
- github.comhttps://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_mofcomp_execution.yml
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: "Windows: Detect Suspicious mofcomp.exe Execution from Scripts or Temp Paths"
id: 214fbe46-31b1-4bf5-b8b6-36b851adbed9
status: test
description: This rule identifies execution of mofcomp.exe when it is launched as a child of common scripting shells (cmd.exe, PowerShell, pwsh, wsl.exe, wscript.exe, cscript.exe) or when the command line includes suspicious TEMP/AppData locations. It focuses on cases where mofcomp may be used to import attacker-controlled MOF content into the WMI repository. The detection relies on Windows process creation telemetry fields for process image names, parent image paths, and command-line content, and it excludes likely benign invocations tied to WmiPrvSE.exe with specific .mof handling in C:\Windows\TEMP.
references:
- https://thedfirreport.com/2022/07/11/select-xmrig-from-sqlserver/
- https://github.com/The-DFIR-Report/Sigma-Rules/blob/75260568a7ffe61b2458ca05f6f25914efb44337/win_mofcomp_execution.yml
- https://learn.microsoft.com/en-us/windows/win32/wmisdk/mofcomp
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_mofcomp_execution.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2022-07-12
modified: 2023-04-11
tags:
- attack.stealth
- attack.t1218
logsource:
category: process_creation
product: windows
detection:
selection_img:
- Image|endswith: \mofcomp.exe
- OriginalFileName: mofcomp.exe
selection_case:
- ParentImage|endswith:
- \cmd.exe
- \powershell.exe
- \pwsh.exe
- \wsl.exe
- \wscript.exe
- \cscript.exe
- CommandLine|contains:
- \AppData\Local\Temp
- \Users\Public\
- \WINDOWS\Temp\
- "%temp%"
- "%tmp%"
- "%appdata%"
filter_main_wmiprvse:
ParentImage: C:\Windows\System32\wbem\WmiPrvSE.exe
CommandLine|contains: C:\Windows\TEMP\
CommandLine|endswith: .mof
filter_optional_null_parent:
CommandLine|contains: C:\Windows\TEMP\
CommandLine|endswith: .mof
condition: all of selection_* and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
- Unknown
level: high
license: DRL-1.1
related:
- id: 1dd05363-104e-4b4a-b963-196a534b03a1
type: derived