title: File Creation by Office Applications
id: 8c6fd6fc-28fc-4597-a86a-fc1de20b039d
description: This rule will monitor executable and script file creation by office applications. Please add more file extensions or magic bytes to the logic of your choice.  
references:
    - https://thedfirreport.com/2021/03/29/sodinokibi-aka-revil-ransomware/
    - https://github.com/vadim-hunter/Detection-Ideas-Rules/blob/main/Threat%20Intelligence/The%20DFIR%20Report/20210329_Sodinokibi_(aka_REvil)_Ransomware.yaml
author: "Vadim Khrykov (ThreatIntel), Cyb3rEng (Rule)"
tags:
    - attack.t1204.002
    - attack.t1047
    - attack.t1218.010
    - attack.execution
    - attack.defense_evasion
status: experimental
date: 2021/08/23
logsource:
  product: windows
  category: file_event
detection:
  #useful_information: Please add more file extensions and magic bytes to the logic of your choice. 
  selection1:
    Image|endswith:
      - 'winword.exe'
      - 'excel.exe'
      - 'powerpnt.exe'
      - 'outlook.exe'
  selection2:
    FileName|endswith:
      - ".exe"
      - ".dll"
      - ".ocx"
      - ".com"
      - ".ps1"
      - ".vbs"
      - ".sys"
      - ".bat"
      - ".scr"
      - ".proj"
  selection3:
    FileMagicBytes|startswith:
      - "4D5A"
  condition: selection1 and (selection2 or selection3)
falsepositives:
  - Unknown
level: high
