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Description

The following analytic detects the addition of a new owner to a Service Principal within an Azure AD tenant. It leverages Azure Active Directory events from the AuditLog log category to identify this activity. This behavior is significant because Service Principals do not support multi-factor authentication or conditional access policies, making them a target for adversaries seeking persistence or privilege escalation. If confirmed malicious, this activity could allow attackers to maintain access to the Azure AD environment with single-factor authentication, potentially leading to unauthorized access and control over critical resources.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-28
  • Author: Mauricio Velazco, Gowthamaraj Rajendran, Splunk
  • ID: 7ddf2084-6cf3-4a44-be83-474f7b73c701

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1098 Account Manipulation Persistence, Privilege Escalation
Kill Chain Phase
  • Installation
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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 `azure_monitor_aad`  operationName="Add owner to application" 
| rename properties.* as * 
| rename initiatedBy.user.userPrincipalName as initiatedBy 
| rename targetResources{}.userPrincipalName as newOwner 
| rename targetResources{}.modifiedProperties{}.newValue as displayName 
| eval displayName = mvindex(displayName,1) 
| where initiatedBy!=newOwner 
| stats count min(_time) as firstTime max(_time) as lastTime values(displayName) as displayName by initiatedBy, result, operationName, newOwner 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `azure_ad_service_principal_owner_added_filter`

Macros

The SPL above uses the following Macros:

:information_source: azure_ad_service_principal_owner_added_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • operationName
  • properties.initiatedBy.user.userPrincipalName
  • properties.targetResources{}.userPrincipalName
  • properties.targetResources{}.modifiedProperties{}.newValue
  • properties.result

How To Implement

You must install the latest version of Splunk Add-on for Microsoft Cloud Services from Splunkbase(https://splunkbase.splunk.com/app/3110/#/details). You must be ingesting Azure Active Directory events into your Splunk environment through an EventHub. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the AuditLog log category.

Known False Positives

Administrator may legitimately add new owners for Service Principals. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
54.0 60 90 A new owner was added for service principal $displayName$ by $initiatedBy$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 4