Sigma rule: Azure AD Health Service Agents Registry Keys Access

Rule

Title

Azure AD Health Service Agents Registry Keys Access

Status

test

Level

medium

Author

Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research), MSTIC

Date

2021-08-26

Modified

2022-10-09

File

rules/windows/builtin/security/win_security_aadhealth_svc_agent_regkey_access.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

This detection uses Windows security events to detect suspicious access attempts to the registry key values and sub-keys of Azure AD Health service agents (e.g AD FS).
Information from AD Health service agents can be used to potentially abuse some of the features provided by those services in the cloud (e.g. Federation).
This detection requires an access control entry (ACE) on the system access control list (SACL) of the following securable object: HKLM:\SOFTWARE\Microsoft\ADHealthAgent.
Make sure you set the SACL to propagate to its sub-keys.

Log source

product

windows

service

security

Detection

selection:
    EventID:
        - 4656
        - 4663
    ObjectType: 'Key'
    ObjectName: '\REGISTRY\MACHINE\SOFTWARE\Microsoft\ADHealthAgent'
filter:
    ProcessName|contains:
        - 'Microsoft.Identity.Health.Adfs.DiagnosticsAgent.exe'
        - 'Microsoft.Identity.Health.Adfs.InsightsService.exe'
        - 'Microsoft.Identity.Health.Adfs.MonitoringAgent.Startup.exe'
        - 'Microsoft.Identity.Health.Adfs.PshSurrogate.exe'
        - 'Microsoft.Identity.Health.Common.Clients.ResourceMonitor.exe'
condition: selection and not filter

False positives (as the rule lists them)

• Unknown

Tags

• attack.discovery
• attack.t1012

MITRE ATT&CK ids this rule names

• T1012

References

• https://o365blog.com/post/hybridhealthagent/
• https://github.com/OTRF/Set-AuditRule/blob/c3dec5443414231714d850565d364ca73475ade5/rules/registry/aad_connect_health_service_agent.yml

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/builtin/security/win_security_aadhealth_svc_agent_regkey_access.yml