Uncommon AddinUtil.EXE CommandLine Execution — Sigma Rule

Rule metadata and linked tags

Author: Michael McKinley (@McKinleyMike), Tony Latteri (@TheLatteri). Source status: test; severity: medium. Source dates: 2023-09-18 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: a405ffa9360d5adb49585982983dca95a53e7788699d320b0ff433fe3cdc854c

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: Uncommon AddinUtil.EXE CommandLine Execution
id: 4f2cd9b6-4a17-440f-bb2a-687abb65993a
status: test
description: |
    Detects execution of the Add-In deployment cache updating utility (AddInutil.exe) with uncommon Addinroot or Pipelineroot paths. An adversary may execute AddinUtil.exe with uncommon Addinroot/Pipelineroot paths that point to the adversaries Addins.Store payload.
references:
    - https://www.blue-prints.blog/content/blog/posts/lolbin/addinutil-lolbas.html
author: Michael McKinley (@McKinleyMike), Tony Latteri (@TheLatteri)
date: 2023-09-18
tags:
    - attack.stealth
    - attack.t1218
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\addinutil.exe'
        - OriginalFileName: 'AddInUtil.exe'
    selection_cli:
        CommandLine|contains:
            - '-AddInRoot:'
            - '-PipelineRoot:'
    filter_main_addinroot:
        CommandLine|contains:
            - '-AddInRoot:"C:\Program Files (x86)\Common Files\Microsoft Shared\VSTA'
            - '-AddInRoot:C:\Program Files (x86)\Common Files\Microsoft Shared\VSTA'
            - '-PipelineRoot:"C:\Program Files (x86)\Common Files\Microsoft Shared\VSTA'
            - '-PipelineRoot:C:\Program Files (x86)\Common Files\Microsoft Shared\VSTA'
    condition: all of 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