Microsoft 365 Exchange DKIM Signing Configuration Disabled

Microsoft 365 Exchange DKIM Signing Configuration Disablededit

Identifies when a DomainKeys Identified Mail (DKIM) signing configuration is disabled in Microsoft 365. With DKIM in Microsoft 365, messages that are sent from Exchange Online will be cryptographically signed. This will allow the receiving email system to validate that the messages were generated by a server that the organization authorized and were not spoofed.

Rule type: query

Rule indices:

  • filebeat-*
  • logs-o365*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-30m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Cloud
  • Microsoft 365
  • Continuous Monitoring
  • SecOps
  • Data Protection
  • Persistence

Version: 101 (version history)

Added (Elastic Stack release): 7.11.0

Last modified (Elastic Stack release): 8.6.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positivesedit

Disabling a DKIM configuration may be done by a system or network administrator. Verify that the configuration change was expected. Exceptions can be added to this rule to filter expected behavior.

Investigation guideedit


Rule queryedit

event.dataset:o365.audit and event.provider:Exchange and
event.category:web and event.action:"Set-DkimSigningConfig" and
o365.audit.Parameters.Enabled:False and event.outcome:success

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 101 (8.6.0 release)
  • Formatting only
Version 100 (8.5.0 release)
  • Formatting only
Version 8 (8.4.0 release)
  • Formatting only
Version 6 (8.2.0 release)
  • Formatting only
Version 5 (8.1.0 release)
  • Formatting only
Version 4 (7.13.0 release)
  • Formatting only
Version 3 (7.12.0 release)
  • Formatting only
Version 2 (7.11.2 release)
  • Formatting only