Microsoft 365 Exchange Transport Rule Creation
editMicrosoft 365 Exchange Transport Rule Creation
editIdentifies a transport rule creation in Microsoft 365. Exchange Online mail transport rules should be set to not forward email to domains outside of your organization as a best practice. An adversary may create transport rules to exfiltrate data.
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: 4 (version history)
Added (Elastic Stack release): 7.11.0
Last modified (Elastic Stack release): 7.13.0
Rule authors: Elastic
Rule license: Elastic License v2
Potential false positives
editA new transport rule may be created 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
editConfig
The Microsoft 365 Fleet integration, Filebeat module, or similarly structured data is required to be compatible with this rule.
Rule query
editevent.dataset:o365.audit and event.provider:Exchange and event.category:web and event.action:"New-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 4 (7.13.0 release)
-
- Formatting only
- Version 3 (7.12.0 release)
-
- Formatting only
- Version 2 (7.11.2 release)
-
- Formatting only