Suspicious Azure Active Directory Hybrid Health AD FS New Server (via activitylogs)

title: Suspicious Azure Active Directory Hybrid Health AD FS New Server (via activitylogs)
id: fb60906b-6b3a-548f-9fce-31ad13589d0e
status: stable
description: This rule detects this detection uses azureactivity logs (Administrative category) to identify the creation or update of a server instance in an Azure AD Hybrid health AD FS service. A threat actor can create a new AD Health ADFS service and create a fake server instance to spoof AD FS signing logs. There is no need to compromise an on-prem AD FS server. This can be done programmatically via HTTP requests to Azure.
references:
    - https://attack.mitre.org/techniques/T1578/
    - https://o365blog.com/post/hybridhealthagent/
author: Huntrule Team
date: 2026-07-19
tags:
    - attack.defense-impairment
    - attack.t1578
logsource:
    product: azure
    service: activitylogs
detection:
    selection:
        CategoryValue: 'Administrative'
        ResourceProviderValue: 'Microsoft.ADHybridHealthService'
        ResourceId|contains: 'AdFederationService'
        OperationNameValue: 'Microsoft.ADHybridHealthService/services/servicemembers/action'
    condition: selection
falsepositives:
    - Unknown
level: medium