Microsoft Entra ID Hybrid Health AD FS Service Delete

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

This detection uses AzureActivity logs (Administrative category) to identify the deletion of an Microsoft Entra ID 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 no longer needed via HTTP requests to Azure. More information is available in this blog https://o365blog.com/post/hybridhealthagent/

MITRE ATT&CK coverage

Tactic	Techniques
Defense Impairment	`T1578.003` Modify Cloud Compute Infrastructure: Delete Cloud Instance

Event coverage

Provider	Event
Azure-Microsoft.ADHybridHealthService	Microsoft.ADHybridHealthService/services/delete

Rules detecting the same action

Other rules on this platform that filter on the same API call or operation.

Rule body kusto

id: 86a036b2-3686-42eb-b417-909fc0867771
name: Microsoft Entra ID Hybrid Health AD FS Service Delete
description: |
  'This detection uses AzureActivity logs (Administrative category) to identify the deletion of an Microsoft Entra ID 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 no longer needed via HTTP requests to Azure.
  More information is available in this blog https://o365blog.com/post/hybridhealthagent/'
severity: Medium
status: Available 
requiredDataConnectors:
  - connectorId: AzureActivity
    dataTypes:
      - AzureActivity
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - DefenseEvasion
relevantTechniques:
  - T1578.003
tags:
  - SimuLand
query: |
  AzureActivity
  | where CategoryValue =~ 'Administrative'
  | where ResourceProviderValue =~ 'Microsoft.ADHybridHealthService'
  | where _ResourceId has 'AdFederationService'
  | where OperationNameValue =~ 'Microsoft.ADHybridHealthService/services/delete'
  | 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])
  | 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

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 =~ 'Microsoft.ADHybridHealthService/services/delete'

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: `project-away`

| project-away claimsJson

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`CategoryValue`	eq	`Administrative`
`OperationNameValue`	eq	`Microsoft.ADHybridHealthService/services/delete`
`ResourceProviderValue`	eq	`Microsoft.ADHybridHealthService`
`_ResourceId`	match	`AdFederationService` transforms: `term`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

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

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

Microsoft Entra ID Hybrid Health AD FS Service Delete

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `where`

Stage 6: `extend`

Stage 7: `extend`

Stage 8: `project-away`

Indicators

Output fields

Keyboard shortcuts

Search operators

Microsoft Entra ID Hybrid Health AD FS Service Delete

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where

Stage 5: where

Stage 6: extend

Stage 7: extend

Stage 8: project-away

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `where`

Stage 6: `extend`

Stage 7: `extend`

Stage 8: `project-away`