Windows Process Creation: Excel DCOM Child Processes Linked to ActivateMicrosoftApp

Alerts when excel.exe spawns foxprow.exe, schdplus.exe, or winproj.exe, consistent with suspicious Excel DCOM automation activity.

FreeReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
Aaron Stratton (SigmaHQ), DRL 1.1
Published
2023-11-13
Updated
2026-07-30
title: "Windows Process Creation: Excel DCOM Child Processes Linked to ActivateMicrosoftApp"
id: 8c8e6f4f-908f-4607-a05b-35fc291237e6
status: test
description: This rule flags suspicious child processes spawned by excel.exe where the child executable name matches foxprow.exe, schdplus.exe, or winproj.exe. Such behavior can indicate lateral movement attempts using an Excel DCOM automation pattern, where Excel is leveraged to execute or relay actions to other components. The detection relies on Windows process creation telemetry, including parent and child process image paths and OriginalFileName metadata.
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
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_office_excel_dcom_lateral_movement.yml
author: Aaron Stratton, Huntrule Team
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
license: DRL-1.1
related:
  - id: 551d9c1f-816c-445b-a7a6-7a3864720d60
    type: derived