Persistence via Microsoft Outlook VBA

Elastic Stack Serverless Security

Detects attempts to establish persistence on an endpoint by installing a rogue Microsoft Outlook VBA Template.

Rule type: eql

Rule indices:

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

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (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:

• https://www.mdsec.co.uk/2020/11/a-fresh-outlook-on-mail-based-persistence/
• https://www.linkedin.com/pulse/outlook-backdoor-using-vba-samir-b-/

Tags:

• Elastic
• Host
• Windows
• Threat Detection
• Persistence

Version: 6

Rule authors:

• Elastic

Rule license: Elastic License v2

file where event.type != "deletion" and
 file.path : "C:\\Users\\*\\AppData\\Roaming\\Microsoft\\Outlook\\VbaProject.OTM"

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Persistence
  • ID: TA0003
  • Reference URL: https://attack.mitre.org/tactics/TA0003/

• Technique:

  • Name: Office Application Startup
  • ID: T1137
  • Reference URL: https://attack.mitre.org/techniques/T1137/