huntrule

M365 Audit: Successful Intune Company Portal login via Cmsi

Flags successful Company Portal (Intune) logins via Cmsi audit events that may indicate Conditional Access bypass attempts.

FreeReviewedSigma · High · v4
Product
m365
Service
audit
Author
Josh Nickels, Marius Rothenbücher (SigmaHQ), DRL 1.1
Published
2025-01-08
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Initial Access → Defense Evasion

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule matches successful UserLoggedIn audit events for the Microsoft Intune Company Portal application when the request type is Cmsi:Cmsi. Such logins may be used to gain access that depends on Conditional Access and Intune device trust state, making them relevant to attacker attempts to bypass policy controls. It relies on M365 audit telemetry fields including Operation, ApplicationId, ResultStatus, RequestType, and the ObjectId filter used to narrow the event scope.

Reporting behind it

Related detections9 linkedT1078 — drag to rearrange
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Malicious Network Login Performed to Multiple Targets (via security)
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M365 Audit: Successful Intune Company Portal login via Cmsi
Pivot detection · T1078 · 9 related

Changelog

v4
  1. v4
    Candidate ingested via manual entry.2026-07-31
  2. v3
    Candidate ingested via manual entry.2026-07-31
  3. v2
    Candidate ingested via manual entry.2026-07-31
  4. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.