Detection: Azure AD Service Principal Privilege Escalation

Updated Date: 2025-01-06 ID: 29eb39d3-2bc8-49cc-99b3-35593191a588 Author: Dean Luxton Type: TTP Product: Splunk Enterprise Security

Description

This detection identifies when an Azure Service Principal elevates privileges by adding themself to a new app role assignment.

Search

1`azure_monitor_aad` category=AuditLogs operationName="Add app role assignment to service principal" properties.initiatedBy.app.displayName=* properties.result=Success  
2| spath path=properties{}.targetResources{}.modifiedProperties{} output=targetResources 
3| stats min(_time) as _time values(eval(mvfilter(match(targetResources, "AppRole.Value")))) as appRole, values(eval(mvfilter(match(targetResources, "ServicePrincipal.DisplayName")))) as targetServicePrincipal values(eval(mvindex('properties.targetResources{}.displayName',0))) as targetAppContext values(user_agent) as user_agent values(identity) as servicePrincipal values(properties.initiatedBy.app.servicePrincipalId) as servicePrincipalId by operationName tenantId correlationId 
4| spath input=appRole path=newValue output=appRole 
5| spath input=targetServicePrincipal path=newValue output=targetServicePrincipal 
6| eval appRole=trim(replace(appRole, "\"", "")), targetServicePrincipal=trim(replace(targetServicePrincipal, "\"", "")) 
7| where servicePrincipal=targetServicePrincipal 
8| table _time operationName servicePrincipal servicePrincipalId appRole targetAppContext user_agent tenantId correlationId 
9| `azure_ad_service_principal_privilege_escalation_filter`

Data Source

Name	Platform	Sourcetype	Source
Azure Active Directory Add app role assignment to service principal	Azure	`'azure:monitor:aad'`	`'Azure AD'`

Macros Used

Name	Value
azure_monitor_aad	`sourcetype=azure:monitor:aad`
azure_ad_service_principal_privilege_escalation_filter	`search *`

azure_ad_service_principal_privilege_escalation_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK

+ Kill Chain Phases

+ NIST

+ CIS

- Threat Actors

ID	Technique	Tactic
T1098.003	Additional Cloud Roles	Persistence
T1098	Account Manipulation	Privilege Escalation

Exploitation

Installation

DE.CM

CIS 10

LAPSUS$

Scattered Spider

HAFNIUM

Lazarus Group

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting	Value
Disabled	true
Cron Schedule	`0 * * * *`
Earliest Time	`-70m@m`
Latest Time	`-10m@m`
Schedule Window	`auto`
Creates Notable	Yes
Rule Title	`%name%`
Rule Description	`%description%`
Notable Event Fields	user, dest
Creates Risk Event	True

This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

The Splunk Add-on for Microsoft Cloud Services add-on is required to ingest EntraID audit logs via Azure EventHub. See reference for links for further details on how to onboard this log source.

Known False Positives

Unknown

Associated Analytic Story

Azure Active Directory Privilege Escalation

Risk Based Analytics (RBA)

Risk Message:

Service Principal $servicePrincipal$ has elevated privileges by adding themself to app role $appRole$

Risk Object	Risk Object Type	Risk Score	Threat Objects
servicePrincipal	user	100	user_agent

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	✅ Passing	N/A	N/A	N/A
Unit	✅ Passing	Dataset	`Azure AD`	`azure:monitor:aad`
Integration	✅ Passing	Dataset	`Azure AD`	`azure:monitor:aad`

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 1