Azure AD Health Monitoring Agent Registry Keys Access

 1title: Azure AD Health Monitoring Agent Registry Keys Access
 2id: ff151c33-45fa-475d-af4f-c2f93571f4fe
 3status: test
 4description: |
 5    This detection uses Windows security events to detect suspicious access attempts to the registry key of Azure AD Health monitoring agent.
 6    This detection requires an access control entry (ACE) on the system access control list (SACL) of the following securable object HKLM\SOFTWARE\Microsoft\Microsoft Online\Reporting\MonitoringAgent.    
 7references:
 8    - https://o365blog.com/post/hybridhealthagent/
 9    - https://github.com/OTRF/Set-AuditRule/blob/c3dec5443414231714d850565d364ca73475ade5/rules/registry/aad_connect_health_monitoring_agent.yml
10author: Roberto Rodriguez (Cyb3rWard0g), OTR (Open Threat Research), MSTIC
11date: 2021-08-26
12modified: 2022-10-09
13tags:
14    - attack.discovery
15    - attack.t1012
16logsource:
17    product: windows
18    service: security
19detection:
20    selection:
21        EventID:
22            - 4656
23            - 4663
24        ObjectType: 'Key'
25        ObjectName: '\REGISTRY\MACHINE\SOFTWARE\Microsoft\Microsoft Online\Reporting\MonitoringAgent'
26    filter:
27        ProcessName|contains:
28            - 'Microsoft.Identity.Health.Adfs.DiagnosticsAgent.exe'
29            - 'Microsoft.Identity.Health.Adfs.InsightsService.exe'
30            - 'Microsoft.Identity.Health.Adfs.MonitoringAgent.Startup.exe'
31            - 'Microsoft.Identity.Health.Adfs.PshSurrogate.exe'
32            - 'Microsoft.Identity.Health.Common.Clients.ResourceMonitor.exe'
33    condition: selection and not filter
34falsepositives:
35    - Unknown
36level: medium

References

• Spoofing Azure AD sign-ins logs by imitating AD FS Hybrid Health Agent

  

  Azure AD Connect Health is a feature that allows viewing the health of on-prem hybrid infrastructure components, including Azure AD Connect and AD FS servers. Health information is gathered by agents installed on each on-prem hybrid server. Since March 2021, also AD FS sign-in events are gathered and sent to Azure AD. In this write-up (based on a Threat Analysis report by Secureworks), I’ll explain how anyone with a local administrator access to AD FS server (or proxy), can create arbitrary sign-ins events to Azure AD sign-ins log. Moreover, I’ll show how Global Administrators can register fake agents to Azure AD - even for tenants not using AD FS at all.

  
  Read More

• Set-AuditRule/rules/registry/aad_connect_health_monitoring_agent.yml at c3dec5443414231714d850565d364ca73475ade5 · OTRF/Set-AuditRule

  

  Useful access control entries (ACE) on system access control list (SACL) of securable objects to find potential adversarial activity - OTRF/Set-AuditRule

  
  Read More

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