Sigma Rule Library

Potential Exploitation Attempt From Office Application

Detects Office applications executing a child process that includes directory traversal patterns. This could be an attempt to exploit CVE-2022-30190 (MSDT RCE) or CVE-2021-40444 (MSHTML RCE)

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Detection logic

selection

ParentImage|endswith:
  - \winword.exe
  - \excel.exe
  - \powerpnt.exe
  - \msaccess.exe
  - \mspub.exe
  - \eqnedt32.exe
  - \visio.exe
CommandLine|contains:
  - ../../../..
  - ..\..\..\..
  - ..//..//..//..

Condition

selection

Raw YAML

title: Potential Exploitation Attempt From Office Application
id: 868955d9-697e-45d4-a3da-360cefd7c216
status: test
description: Detects Office applications executing a child process that includes directory traversal patterns. This could be an attempt to exploit CVE-2022-30190 (MSDT RCE) or CVE-2021-40444 (MSHTML RCE)
references:
    - https://twitter.com/sbousseaden/status/1531653369546301440
    - https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2021-40444
    - https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-30190
author: Christian Burkard (Nextron Systems), @SBousseaden (idea)
date: 2022-06-02
modified: 2023-02-04
tags:
    - attack.execution
    - cve.2021-40444
    - detection.emerging-threats
    - attack.stealth
logsource:
    product: windows
    category: process_creation
detection:
    selection:
        ParentImage|endswith:
            - '\winword.exe'
            - '\excel.exe'
            - '\powerpnt.exe'
            - '\msaccess.exe'
            - '\mspub.exe'
            - '\eqnedt32.exe'
            - '\visio.exe'
        CommandLine|contains:
            - '../../../..'
            - '..\..\..\..'
            - '..//..//..//..'
    condition: selection
falsepositives:
    - Unknown
level: high

False positives

  • Unknown

References

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