huntrule

Windows msiexec.exe Execution from Uncommon Directory

Alerts when msiexec.exe starts from a non-standard path, which may indicate masquerading.

FreeUnreviewedSigmahighv1
title: Windows msiexec.exe Execution from Uncommon Directory
id: 4dde7b57-b4d4-46d8-a189-cb72134edfd6
status: test
description: This rule flags process creation events where msiexec.exe is executed from a directory other than the typical Windows locations. Attackers may masquerade or proxy trusted installer execution to blend into normal activity while running malicious payloads. Detection relies on Windows process creation telemetry fields for the executable path and the OriginalFileName.
references:
  - https://twitter.com/200_okay_/status/1194765831911215104
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_msiexec_masquerading.yml
author: Florian Roth (Nextron Systems), Huntrule Team
date: 2019-11-14
modified: 2023-02-21
tags:
  - attack.stealth
  - attack.t1036.005
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    - Image|endswith: \msiexec.exe
    - OriginalFileName: \msiexec.exe
  filter:
    Image|startswith:
      - C:\Windows\System32\
      - C:\Windows\SysWOW64\
      - C:\Windows\WinSxS\
  condition: selection and not filter
falsepositives:
  - Unknown
level: high
license: DRL-1.1
related:
  - id: e22a6eb2-f8a5-44b5-8b44-a2dbd47b1144
    type: derived

What it detects

This rule flags process creation events where msiexec.exe is executed from a directory other than the typical Windows locations. Attackers may masquerade or proxy trusted installer execution to blend into normal activity while running malicious payloads. Detection relies on Windows process creation telemetry fields for the executable path and the OriginalFileName.

Known false positives

  • Unknown

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