Entra ID Register Device with Unusual User Agent (Azure AD Join)
Detects successful Microsoft Entra ID audit events for Register device where additional details indicate an Azure AD join and the recorded user agent is not one of the common native registration clients (Dsreg,…
Description
Detects successful Microsoft Entra ID audit events for Register device where additional details indicate an Azure AD join and the recorded user agent is not one of the common native registration clients (Dsreg, DeviceRegistrationClient, or Dalvik-based Android enrollment). Legitimate Windows and standard mobile enrollment flows often present predictable user-agent strings; unexpected clients may reflect scripted registration, third-party tooling, or adversary-driven device registration used for persistence or token abuse. Baseline approved provisioning tools and MDM integrations before tuning.
Detection logic
Its licence does not clear it for publishing here
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Detection requirements
- Platform
- ContainersESXiIaaSIdentity ProviderLinuxmacOSNetwork DevicesOffice SuiteSaaSWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- event_index
Known benign triggers
- Custom device management agents, OEM enrollment clients, or updated Microsoft clients that use new user-agent strings may match. Add exclusions for known `azure.auditlogs.properties.userAgent` values or enrollment programs after review.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| github.com/dirkjanm/ROADtools | 16from 2 sources |
| learn.microsoft.com/en-us/entra/identity/devices/concept-directory-join | Only this detection cites it |
From the source
- At source
- Open at source
- Upstream identifier
- d4695889-0410-4e7b-a4aa-59be525a11a6
- Tagged by the source as
- Data Source: AzureData Source: Microsoft Entra IDData Source: Microsoft Entra ID Audit LogsDomain: CloudDomain: IdentityNoise: LowPerformance: NormalPlatform: Entra IDResources: Investigation GuideRule Type: Custom Query (KQL)Tactic: PersistenceUse Case: Threat Detection
Licence
- Published under
- Elastic License 2.0Read the licence
- Attribution
- Required
Authorship
- Written by
- Published
- Sep 20, 2026
- Version
- 3