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Detection rules › Sigma

Potential Excel.EXE DCOM Lateral Movement Via ActivateMicrosoftApp

Status
test
Severity
high
Log source
product windows, category process_creation
Author
Aaron Stratton
Source
github.com/SigmaHQ/sigma

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

MITRE ATT&CK coverage

TacticTechniques
Lateral MovementT1021.003 Remote Services: Distributed Component Object Model

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

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

Stages and Predicates

Stage 0: condition

all of selection_*

Stage 1: selection_parent

selection_parent:
    ParentImage|endswith: '\excel.exe'

Stage 2: selection_child

selection_child:
    - OriginalFileName:
      - 'foxprow.exe'
      - 'schdplus.exe'
      - 'winproj.exe'
    - Image|endswith:
      - '\foxprow.exe'
      - '\schdplus.exe'
      - '\winproj.exe'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imageends_with
  • \foxprow.exe
  • \schdplus.exe
  • \winproj.exe
OriginalFileNameeq
  • foxprow.exe
  • schdplus.exe
  • winproj.exe
ParentImageends_with
  • \excel.exe corpus 8 (sigma 8)