Microsoft Entra ID Hybrid Health AD FS Suspicious Application

Status: available
Severity: medium
Time window: 1d
Source: github.com/Azure/Azure-Sentinel

This detection uses AzureActivity logs (Administrative category) to identify a suspicious application adding a server instance to an Microsoft Entra ID Hybrid Health AD FS service or deleting the AD FS service instance. Usually the Microsoft Entra ID Connect Health Agent application with ID cf6d7e68-f018-4e0a-a7b3-126e053fb88d and ID cb1056e2-e479-49de-ae31-7812af012ed8 is used to perform those operations.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1528` Steal Application Access Token
Lateral Movement	`T1550` Use Alternate Authentication Material

Telemetry coverage

Platform	Record / event type
Azure	Activity Log event `Microsoft.ADHybridHealthService/services/delete`: Deletes a service instance in the tenant.
Azure	Activity Log event `Microsoft.ADHybridHealthService/services/servicemembers/action`: Creates or updates a server instance in the service.

Rules detecting the same action

These rules filter on the same operation.

Rule body

id: d9938c3b-16f9-444d-bc22-ea9a9110e0fd
name: Microsoft Entra ID Hybrid Health AD FS Suspicious Application
description: |
  'This detection uses AzureActivity logs (Administrative category) to identify a suspicious application adding a server instance to an Microsoft Entra ID Hybrid Health AD FS service or deleting the AD FS service instance.
  Usually the Microsoft Entra ID Connect Health Agent application with ID cf6d7e68-f018-4e0a-a7b3-126e053fb88d and ID cb1056e2-e479-49de-ae31-7812af012ed8 is used to perform those operations.'
severity: Medium
status: Available 
requiredDataConnectors:
  - connectorId: AzureActivity
    dataTypes:
      - AzureActivity
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CredentialAccess
  - DefenseEvasion
relevantTechniques:
  - T1528
  - T1550
tags:
  - SimuLand
query: |
  // Microsoft Entra ID Connect Health Agent - cf6d7e68-f018-4e0a-a7b3-126e053fb88d
  // Microsoft Entra ID Connect - cb1056e2-e479-49de-ae31-7812af012ed8
  let appList = dynamic(['cf6d7e68-f018-4e0a-a7b3-126e053fb88d','cb1056e2-e479-49de-ae31-7812af012ed8']);
  let operationNamesList = dynamic(['Microsoft.ADHybridHealthService/services/servicemembers/action','Microsoft.ADHybridHealthService/services/delete']);
  AzureActivity
  | where CategoryValue =~ 'Administrative'
  | where ResourceProviderValue =~ 'Microsoft.ADHybridHealthService'
  | where _ResourceId has 'AdFederationService'
  | where OperationNameValue in~ (operationNamesList)
  | extend claimsJson = parse_json(Claims)
  | extend AppId = tostring(claimsJson.appid), AccountName = tostring(claimsJson.name), Name = tostring(split(Caller,'@',0)[0]), UPNSuffix = tostring(split(Caller,'@',1)[0])
  | where AppId !in (appList)
  | project-away claimsJson
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: Caller
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: CallerIpAddress
version: 2.0.3
kind: Scheduled

Stages and Predicates

Parameters

let appList = dynamic(['cf6d7e68-f018-4e0a-a7b3-126e053fb88d','cb1056e2-e479-49de-ae31-7812af012ed8']);
let operationNamesList = dynamic(['Microsoft.ADHybridHealthService/services/servicemembers/action','Microsoft.ADHybridHealthService/services/delete']);

Stage 1: `source`

AzureActivity

Stage 2: `where`

| where CategoryValue =~ 'Administrative'

Stage 3: `where`

| where ResourceProviderValue =~ 'Microsoft.ADHybridHealthService'

Stage 4: `where`

| where _ResourceId has 'AdFederationService'

Stage 5: `where`

| where OperationNameValue in~ (operationNamesList)

Stage 6: `extend`

| extend claimsJson = parse_json(Claims)

Stage 7: `extend`

| extend AppId = tostring(claimsJson.appid), AccountName = tostring(claimsJson.name), Name = tostring(split(Caller,'@',0)[0]), UPNSuffix = tostring(split(Caller,'@',1)[0])

Stage 8: `where`

| where AppId !in (appList)

Stage 9: `project-away`

| project-away claimsJson

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`AppId`	in	`cb1056e2-e479-49de-ae31-7812af012ed8`, `cf6d7e68-f018-4e0a-a7b3-126e053fb88d`	`excludes:AppId` `field:"AppId" value:"cb1056e2-e479-49de-ae31-7812af012ed8"` `field:"AppId" value:"cf6d7e68-f018-4e0a-a7b3-126e053fb88d"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CategoryValue`	eq	`Administrative`	`field:"CategoryValue" kind:eq value:"Administrative"`
`OperationNameValue`	in	`Microsoft.ADHybridHealthService/services/delete` `Microsoft.ADHybridHealthService/services/servicemembers/action`	`field:"azure_ad::operation_name_value" kind:in`
`ResourceProviderValue`	eq	`Microsoft.ADHybridHealthService`	`field:"ResourceProviderValue" kind:eq value:"Microsoft.ADHybridHealthService"`
`_ResourceId`	match	`AdFederationService` transforms: `term`	`field:"_ResourceId" kind:match value:"AdFederationService"`

Output fields

These fields are emitted when the rule matches.

Field	Source
`AccountName`	`extend`
`AppId`	`extend`
`Name`	`extend`
`UPNSuffix`	`extend`

Microsoft Entra ID Hybrid Health AD FS Suspicious Application

MITRE ATT&CK coverage

Telemetry coverage

Rules detecting the same action

Rule body

Stages and Predicates

Parameters

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where

Stage 5: where

Stage 6: extend

Stage 7: extend

Stage 8: where

Stage 9: project-away