Azure Entra ID anomalous user activity risk event

Alerts on Azure AD risk events indicating anomalous user activity via riskEventType=anomalousUserActivity.

FreeReviewedSigma · High · v5

Product: azure
Service: riskdetection
Author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo' (SigmaHQ), DRL 1.1
Published: 2023-09-03
Updated: 2026-07-31

ATT&CK techniques

Persistence → Priv Esc

Recon
Resource Dev
Initial Access
Execution
Persistence
- T1098Account Manipulation
Priv Esc
- T1098Account Manipulation
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags Azure Entra ID Risk Detection events where riskEventType is anomalousUserActivity. Attackers may trigger this by performing unusual actions that alter account or directory state patterns. The detection relies on the riskdetection telemetry emitted by the risk event source, specifically matching riskEventType.

Reporting behind it

Related detections9 linkedT1098 — drag to rearrange

Malicious Cluster-Admin Role Binding Creation (via audit)

Malicious User Password Change Using Current Hash Password - ChangeNTLM - Mimikatz (via security)

Suspicious Account Password Set to Never Expire. (via security)

Malicious Modification of a Computer Account SPN (via security)

Suspicious Massive Group Membership Changes (via security)

Malicious High Risk Active Directory Group Membership Change (via security)

Malicious Account Marked as Sensitive and Cannot Be Delegated Had Its Protection Removed (via security)

Malicious Host Constrained Delegation Settings Changed for Potential Abuse (Rubeus) - Kerberos Only (via security)

Malicious Host Set with Unconstrained Delegation (via security)

Azure Entra ID anomalous user activity risk event

Pivot detection · T1098 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
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.

azure-ad-risk-detection-anomalous-user-activity-riskeventtype-anomaloususeractiv-258b6593

title: Azure Entra ID anomalous user activity risk event
id: 49e80219-7915-4ff7-b0f6-9f82cc6aea52
status: test
description: This rule flags Azure Entra ID Risk Detection events where riskEventType is anomalousUserActivity. Attackers may trigger this by performing unusual actions that alter account or directory state patterns. The detection relies on the riskdetection telemetry emitted by the risk event source, specifically matching riskEventType.
references:
  - https://learn.microsoft.com/en-us/entra/id-protection/concept-identity-protection-risks#anomalous-user-activity
  - https://learn.microsoft.com/en-us/entra/architecture/security-operations-user-accounts#unusual-sign-ins
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/azure/identity_protection/azure_identity_protection_anomalous_user.yml
author: Mark Morowczynski '@markmorow', Gloria Lee, '@gleeiamglo', Huntrule Team
date: 2023-09-03
tags:
  - attack.privilege-escalation
  - attack.t1098
  - attack.persistence
logsource:
  product: azure
  service: riskdetection
detection:
  selection:
    riskEventType: anomalousUserActivity
  condition: selection
falsepositives:
  - We recommend investigating the sessions flagged by this detection in the context of other sign-ins from the user.
level: high
license: DRL-1.1
related:
  - id: 258b6593-215d-4a26-a141-c8e31c1299a6
    type: derived

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