Execution of File Written or Modified by Microsoft Office

Elastic Stack Serverless Security

Identifies an executable created by a Microsoft Office application and subsequently executed. These processes are often launched via scripts inside documents or during exploitation of MS Office applications.

Rule type: eql

Rule indices:

• logs-endpoint.events.*
• winlogbeat-*
• logs-windows.*

Severity: high

Risk score: 21

Runs every: 60m

Searches indices from: now-120m (https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math[Date Math format], see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

• Elastic
• Host
• Windows
• Threat Detection
• Execution

Version: 4

Rule authors:

• Elastic

Rule license: Elastic License v2

sequence with maxspan=2h
  [file where event.type != "deletion" and file.extension : "exe" and
     (process.name : "WINWORD.EXE" or
      process.name : "EXCEL.EXE" or
      process.name : "OUTLOOK.EXE" or
      process.name : "POWERPNT.EXE" or
      process.name : "eqnedt32.exe" or
      process.name : "fltldr.exe" or
      process.name : "MSPUB.EXE" or
      process.name : "MSACCESS.EXE")
  ] by host.id, file.path
  [process where event.type in ("start", "process_started")] by host.id, process.executable

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Execution
  • ID: TA0002
  • Reference URL: https://attack.mitre.org/tactics/TA0002/

• Tactic:

  • Name: Initial Access
  • ID: TA0001
  • Reference URL: https://attack.mitre.org/tactics/TA0001/

• Technique:

  • Name: Phishing
  • ID: T1566
  • Reference URL: https://attack.mitre.org/techniques/T1566/

• Sub-technique:

  • Name: Spearphishing Attachment
  • ID: T1566.001
  • Reference URL: https://attack.mitre.org/techniques/T1566/001/

• Sub-technique:

  • Name: Spearphishing Link
  • ID: T1566.002
  • Reference URL: https://attack.mitre.org/techniques/T1566/002/