SigmaHQ/rules/windows/sysmon/sysmon_office_shell.yml

title: Microsoft Office Product Spawning Windows Shell
status: experimental
description: Detects a Windows command line executable started from Microsoft Word, Excel, Powerpoint, Publisher and Visio.
references:
    - https://www.hybrid-analysis.com/sample/465aabe132ccb949e75b8ab9c5bda36d80cf2fd503d52b8bad54e295f28bbc21?environmentId=100
    - https://mgreen27.github.io/posts/2018/04/02/DownloadCradle.html
author: Michael Haag, Florian Roth
date: 2018/04/06
logsource:
    product: windows
    service: sysmon
detection:
    selection:
        EventID: 1
        ParentImage:
            - '*\WINWORD.EXE'
            - '*\EXCEL.EXE'
            - '*\POWERPNT.exe'
            - '*\MSPUB.exe'
            - '*\VISIO.exe'
            - '*\OUTLOOK.EXE'
        Image:
            - '*\cmd.exe'
            - '*\powershell.exe'
            - '*\wscript.exe'
            - '*\cscript.exe'
            - '*\sh.exe'
            - '*\bash.exe'
            - '*\scrcons.exe'
            - '*\schtasks.exe'  # see https://www.hybrid-analysis.com/sample/b409538c99f99b94a5035d9fa44a506b41be0feb23e89b7e4d272ba791aa6002?environmentId=100
            - '*\regsvr32.exe'  # see https://twitter.com/subTee/status/899283365647458305
            - '*\hh.exe'  # see https://www.hybrid-analysis.com/sample/6abc2b63f1865a847ff7f5a9d49bb944397b36f5503b9718d6f91f93d60f7cd7?environmentId=100
            - '*\wmic.exe'  # see https://mgreen27.github.io/posts/2018/04/02/DownloadCradle.html
            - '*\mshta.exe'  # see https://mgreen27.github.io/posts/2018/04/02/DownloadCradle.html
            - '*\rundll32.exe'  # see https://mgreen27.github.io/posts/2018/04/02/DownloadCradle.html
            - '*\msiexec.exe'  # see https://twitter.com/DissectMalware/status/984252467474026497
    condition: selection
fields:
    - CommandLine
    - ParentCommandLine
falsepositives:
    - unknown
level: high