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Description

The following analytic detects potential privilege escalation threats in Azure Active Directory (AD). The detection is made by running a specific search within the ingested Azure Active Directory events to leverage the AuditLogs log category. This detection is important because it identifies instances where privileged roles that hold elevated permissions are assigned to service principals. This prevents unauthorized access or malicious activities, which occur when these non-human entities access Azure resources to exploit them. False positives might occur since administrators can legitimately assign privileged roles to service principals.

  • Type: TTP

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

  • Last Updated: 2023-12-20
  • Author: Mauricio Velazco, Splunk
  • ID: 5dfaa3d3-e2e4-4053-8252-16d9ee528c41

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1098 Account Manipulation Persistence, Privilege Escalation
T1098.003 Additional Cloud Roles Persistence, Privilege Escalation
Kill Chain Phase
  • Installation
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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 `azure_monitor_aad`  operationName="Add member to role" 
| rename properties.* as * 
| search "targetResources{}.type"=ServicePrincipal 
| rename initiatedBy.user.userPrincipalName as initiatedBy 
| rename targetResources{}.modifiedProperties{}.newValue  as roles 
| eval role=mvindex(roles,1) 
| rename targetResources{}.displayName as apps 
| eval displayName=mvindex(apps,0) 
| lookup privileged_azure_ad_roles azureadrole AS role OUTPUT isprvilegedadrole description 
| search isprvilegedadrole = True 
| stats count min(_time) as firstTime max(_time) as lastTime values(displayName) as displayName by initiatedBy, result, operationName, role 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `azure_ad_privileged_role_assigned_to_service_principal_filter`

Macros

The SPL above uses the following Macros:

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

Lookups

The SPL above uses the following Lookups:

Required fields

List of fields required to use this analytic.

  • _time
  • properties.targetResources{}.type
  • properties.initiatedBy.user.userPrincipalName
  • 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. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the AuditLog log category.

Known False Positives

Administrators may legitimately assign the privileged roles to Service Principals as part of administrative tasks. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
35.0 70 50 A privileged Azure AD role was assigned to the Service Principal $displayName$ initiated 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: 2