Microsoft 365 Exchange Malware Filter Rule Modificationedit
Identifies when a malware filter rule has been deleted or disabled in Microsoft 365. An adversary or insider threat may want to modify a malware filter rule to evade detection.
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 positivesedit
A malware filter rule may be deleted 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
The Microsoft 365 Fleet integration or Filebeat module must be enabled to use this rule.
Rule queryedit
event.dataset:o365.audit and event.provider:Exchange and event.category:web and event.action:("Remove-MalwareFilterRule" or "Disable-MalwareFilterRule") and event.outcome:success
Threat mappingedit
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
-
Technique:
- Name: Impair Defenses
- ID: T1562
- Reference URL: https://attack.mitre.org/techniques/T1562/
Rule version historyedit
- Version 2 (7.11.2 release)
-
- Formatting only