Potential Excel.EXE DCOM Lateral Movement Via ActivateMicrosoftApp

SIGMA detection rule by Aaron Stratton · NOASSERTION

Detects suspicious child processes of Excel which could be an indicator of lateral movement leveraging the "ActivateMicrosoftApp" Excel DCOM object.

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

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

1139c472-7291-40b9-8a14-5f804e64821d

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

Rejected pattern present

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Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

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[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

[[ currentRule.title ]]

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