Office Spawns Suspicious Child Process (Windows Event Log)

id: '19686.34350'
title: Office Spawns Suspicious Child Process
description: 'This use case attempts to identify suspicious child processes spawned
  from a Microsoft Office application -- Threat Actor Association: RomCom (Storm-0978)
  -- Vulnerability Association: CVE-2023-36884'
logic_format: Splunk
logic: '`get_endpoint_data` `get_endpoint_data_winevent` (TERM(EventCode=4688) OR
  "<EventID>4688<" OR Type=Process) (powershell.exe OR pwsh.exe OR cmd.exe OR mshta.exe
  OR wscript.exe OR cscript.exe OR regsvr32.exe OR rundll32.exe OR taskkill.exe OR
  csc.exe OR calc.exe OR control.exe) ((Microsoft OR Office) OR WINWORD.EXE OR EXCEL.EXE
  OR POWERPNT.EXE OR MSACCESS.EXE OR OUTLOOK.EXE OR VISIO.EXE OR WINPROJ.EXE OR ONENOTE.EXE
  OR GRAPH.EXE OR MSPub.EXE OR wordpad.exe) | regex process_name="(?i)(powershell|pwsh|cmd|mshta|wscript|cscript|regsvr32|rundll32|taskkill|csc|calc|control)\.exe"|
  regex parent_process_path="(?i)Microsoft\sOffice|winword|excel|powerpnt|msaccess|outlook|visio|winproj|onenote|graph|mspub|wordpad"
  | table _time, host, user process, parent_*, process_*, signature_id | bin span=1s
  | stats values(*) as * by _time, host, parent_process_name | where match(parent_process_path,"(?i)(Microsoft
  Office)|(WINWORD\.EXE)|(EXCEL\.EXE)|(POWERPNT\.EXE)|(MSACCESS\.EXE)|(OUTLOOK\.EXE)|(ONENOTE\.EXE)|(VISIO\.EXE)|(WINPROJ\.EXE)|(GRAPH\.exe)|(MSPub\.exe)|(WINPROJ.EXE\.exe)|(wordpad\.exe)") '
techniques:
- execution:user execution:malicious file
technique_id:
- T1204.002
data_category:
- Windows event logs
references:
- https://fourcore.io/blogs/cve-2023-36884-ms-office-zero-day-vulnerability