Sigma rule: Azure Active Directory Hybrid Health AD FS Service Delete

Rule

Title

Azure Active Directory Hybrid Health AD FS Service Delete

Status

test

Level

medium

Author

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

Date

2021-08-26

Modified

2026-10-21

File

rules/cloud/azure/activity_logs/azure_aadhybridhealth_adfs_service_delete.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

This detection uses azureactivity logs (Administrative category) to identify the deletion of an Azure AD Hybrid health AD FS service instance in a tenant.
A threat actor can create a new AD Health ADFS service and create a fake server to spoof AD FS signing logs.
The health AD FS service can then be deleted after it is not longer needed via HTTP requests to Azure.

Log source

product

azure

service

activitylogs

Detection

selection:
    category: 'Administrative'
    resourceId|contains: 'AdFederationService'
    operationName: 'MICROSOFT.ADHYBRIDHEALTHSERVICE/SERVICES/DELETE'
condition: selection

False positives (as the rule lists them)

• Legitimate AAD Health AD FS service instances being deleted in a tenant

Tags

• attack.defense-impairment
• attack.t1578.003

MITRE ATT&CK ids this rule names

• T1578.003

References

• https://web.archive.org/web/20220619212736/https://o365blog.com/post/hybridhealthagent/
• https://aadinternals.com/talks/HelSec%20August%202021.pdf
• https://learn.microsoft.com/en-us/azure/role-based-access-control/permissions/identity#microsoftadhybridhealthservice
• https://www.inversecos.com/2023/01/detecting-fake-events-in-azure-sign-in.html

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/cloud/azure/activity_logs/azure_aadhybridhealth_adfs_service_delete.yml