AddinUtil.EXE Execution From Uncommon Directory — Sigma Rule

Rule metadata and linked tags

Author: Michael McKinley (@McKinleyMike), Tony Latteri (@TheLatteri). Source status: test; severity: medium. Source dates: 2023-09-18 / 2025-02-24.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: d5a6c424d8317fde9ed864990144ee3903d7e8d0e4365c633b7fd3842b0df48b

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: AddinUtil.EXE Execution From Uncommon Directory
id: 6120ac2a-a34b-42c0-a9bd-1fb9f459f348
status: test
description: Detects execution of the Add-In deployment cache updating utility (AddInutil.exe) from a non-standard directory.
references:
    - https://www.blue-prints.blog/content/blog/posts/lolbin/addinutil-lolbas.html
author: Michael McKinley (@McKinleyMike), Tony Latteri (@TheLatteri)
date: 2023-09-18
modified: 2025-02-24
tags:
    - attack.stealth
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        - Image|endswith: '\addinutil.exe'
        - OriginalFileName: 'AddInUtil.exe'
    filter_main_legit_location:
        Image|contains:
            - ':\Windows\Microsoft.NET\Framework\'
            - ':\Windows\Microsoft.NET\Framework64\'
            - ':\Windows\Microsoft.NET\FrameworkArm\'
            - ':\Windows\Microsoft.NET\FrameworkArm64\'
            - ':\Windows\WinSxS\'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: medium

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.blue-prints.blog/content/blog/posts/lolbin/addinutil-lolbas.html