M365EXO-026: Email filtered by attachment file type (MS.EXO.9.1)
- Plataforma
- Entra ID / M365
- Categoría
- Advanced Threat Protection
- Severidad
- High
- Pilar de Zero Trust
- Applications & Workloads (peso 2)
- Fixtures de referencia
- 3
- Cobertura de ramas
- Observada: los fixtures prueban los veredictos que ejercitan
- Procedencia
- baseline
Qué comprueba
SCuBA MS.EXO.9.1 requires that emails be filtered by attachment file type, comparable to the Common Attachment Filter. Many malware payloads arrive as click-to-run attachments. Filtering inbound mail by attachment type blocks dangerous file classes before they reach users, reducing the chance of accidental execution.
Valor recomendado
A malware/anti-malware policy with the common attachment type filter enabled (EnableFileFilter = True)
Remediación
Enable the common attachments filter on the anti-malware policy so inbound mail is filtered by attachment file type. Confirm the policy is applied to all recipients and not limited to a subset. Where a comparable third-party gateway provides this filtering, verify it is enabled and covers the same dangerous file classes.
Veredictos probados con fixtures
Cada veredicto de esta tabla está probado por un fixture de referencia en la suite de pruebas que valida el módulo. La tabla se deriva de la última ejecución en verde; no puede editarse a mano.
| Escenario | Veredicto esperado |
|---|---|
| clean | PASS |
| known-bad | FAIL |
| throttled | Not Assessed |
Mapeos a marcos de referencia
- NIST SP 800-53
- SI-3
- CIS M365 Benchmark
- 2.1.11
- MITRE ATT&CK
- T1204.002