Microsoft 365 Exchange Transport Rule Modification
editMicrosoft 365 Exchange Transport Rule Modification
editIdentifies when a transport rule has been disabled or deleted in Microsoft 365. Mail flow rules (also known as transport rules) are used to identify and take action on messages that flow through your organization. An adversary or insider threat may modify a transport rule to exfiltrate data or evade defenses.
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
- Configuration Audit
Version: 2 (version history)
Added (Elastic Stack release): 7.11.0
Last modified (Elastic Stack release): 7.11.2
Rule authors: Elastic
Rule license: Elastic License
Potential false positives
editA transport rule may be modified 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 guide
editThe Microsoft 365 Fleet integration or Filebeat module must be enabled to use this rule.
Rule query
editevent.dataset:o365.audit and event.provider:Exchange and
event.category:web and event.action:("Remove-TransportRule" or
"Disable-TransportRule") and event.outcome:success
Threat mapping
editFramework: MITRE ATT&CKTM
-
Tactic:
- Name: Exfiltration
- ID: TA0010
- Reference URL: https://attack.mitre.org/tactics/TA0010/
-
Technique:
- Name: Transfer Data to Cloud Account
- ID: T1537
- Reference URL: https://attack.mitre.org/techniques/T1537/
Rule version history
edit- Version 2 (7.11.2 release)
-
- Formatting only