Microsoft 365 Exchange Malware Filter Rule Modification
editMicrosoft 365 Exchange Malware Filter Rule Modification
editIdentifies 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: 5m
Searches indices from: now-30m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
References:
Tags:
- Domain: Cloud
- Data Source: Microsoft 365
- Use Case: Configuration Audit
- Tactic: Defense Evasion
Version: 206
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guide
editSetup
editThe Office 365 Logs 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:("Remove-MalwareFilterRule" or "Disable-MalwareFilterRule") and event.outcome:success
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/