Microsoft 365 Exchange Safe Link Policy Disabled

Elastic Stack Serverless Security

Identifies when a Safe Link policy is disabled in Microsoft 365. Safe Link policies for Office applications extend phishing protection to documents that contain hyperlinks, even after they have been delivered to a user.

Rule type: query

Rule indices:

• filebeat-*
• logs-o365*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-30m (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://docs.microsoft.com/en-us/powershell/module/exchange/disable-safelinksrule?view=exchange-ps
• https://docs.microsoft.com/en-us/microsoft-365/security/office-365-security/atp-safe-links?view=o365-worldwide

Tags:

• Elastic
• Cloud
• Microsoft 365
• Continuous Monitoring
• SecOps
• Identity and Access

Version: 5

Rule authors:

• Elastic

Rule license: Elastic License v2

The Office 365 Logs Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule.

event.dataset:o365.audit and event.provider:Exchange and event.category:web and event.action:"Disable-SafeLinksRule" and event.outcome:success

Framework: MITRE ATT&CKTM

• 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/