Potential Excel.EXE DCOM Lateral Movement Via ActivateMicrosoftApp — Sigma Rule

Rule metadata and linked tags

Author: Aaron Stratton. Source status: test; severity: high. Source dates: 2023-11-13 / not supplied.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 2bef8500cbf1f44ecbcfd46c95b092165c3aa09e7c93002b85393d14e35ee56a

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: Potential Excel.EXE DCOM Lateral Movement Via ActivateMicrosoftApp
id: 551d9c1f-816c-445b-a7a6-7a3864720d60
status: test
description: |
    Detects suspicious child processes of Excel which could be an indicator of lateral movement leveraging the "ActivateMicrosoftApp" Excel DCOM object.
references:
    - https://posts.specterops.io/lateral-movement-abuse-the-power-of-dcom-excel-application-3c016d0d9922
    - https://github.com/grayhatkiller/SharpExShell
    - https://learn.microsoft.com/en-us/office/vba/api/excel.xlmsapplication
author: Aaron Stratton
date: 2023-11-13
tags:
    - attack.t1021.003
    - attack.lateral-movement
logsource:
    category: process_creation
    product: windows
detection:
    selection_parent:
        ParentImage|endswith: '\excel.exe'
    selection_child:
        - OriginalFileName:
          - 'foxprow.exe'
          - 'schdplus.exe'
          - 'winproj.exe'
        - Image|endswith:
          - '\foxprow.exe'
          - '\schdplus.exe'
          - '\winproj.exe'
    condition: all of selection_*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://posts.specterops.io/lateral-movement-abuse-the-power-of-dcom-excel-application-3c016d0d9922
• https://github.com/grayhatkiller/SharpExShell
• https://learn.microsoft.com/en-us/office/vba/api/excel.xlmsapplication