ID | Technique | Tactic |
---|---|---|
T1098 | Account Manipulation | Persistence |
T1098.003 | Additional Cloud Roles | Privilege Escalation |
Detection: O365 Privileged Role Assigned To Service Principal
Description
The following analytic detects potential privilege escalation threats in Azure Active Directory (AD). 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. This detection leverages the O365 Universal Audit Log data source.
Search
1`o365_management_activity` Workload=AzureActiveDirectory Operation IN ("Add member to role.","Add eligible member to role.")
2| eval user = ObjectId, src_user = case(match(mvindex('Actor{}.ID',-1),"User"),mvindex('Actor{}.ID',0),match(mvindex('Actor{}.ID',-1),"ServicePrincipal"),mvindex('Actor{}.ID',3),true(),mvindex('Actor{}.ID',0)), object_name = mvindex('ModifiedProperties{}.NewValue', mvfind('ModifiedProperties{}.Name',"Role\.DisplayName")), object_id = mvindex('ModifiedProperties{}.NewValue', mvfind('ModifiedProperties{}.Name',"Role\.TemplateId")), signature = Operation, result = ResultStatus, category = mvindex('Target{}.ID',2)
3| stats count, min(_time) as firstTime, max(_time) as lastTime by src_user, user, category, result, object_name, object_id, signature
4| lookup privileged_azure_ad_roles azuretemplateid as object_id OUTPUT isprvilegedadrole
5| search isprvilegedadrole="TRUE" category!="User"
6| `security_content_ctime(firstTime)`
7| `security_content_ctime(lastTime)`
8| `o365_privileged_role_assigned_to_service_principal_filter`
Data Source
Name | Platform | Sourcetype | Source | Supported App |
---|---|---|---|---|
N/A | N/A | N/A | N/A | N/A |
Macros Used
Name | Value |
---|---|
o365_management_activity | sourcetype=o365:management:activity |
o365_privileged_role_assigned_to_service_principal_filter | search * |
o365_privileged_role_assigned_to_service_principal_filter
is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Annotations
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 |
Implementation
You must install the Splunk Microsoft Office 365 Add-on and ingest Office 365 management activity events.
Known False Positives
Administrators may legitimately assign the privileged roles to Service Principals as part of administrative tasks. Filter as needed.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
A privileged Azure AD role [$object_name$] was assigned to the Service Principal $user$ initiated by $src_user$ | 75 | 75 | 100 |
References
-
https://learn.microsoft.com/en-us/azure/active-directory/roles/permissions-reference
-
https://posts.specterops.io/azure-privilege-escalation-via-service-principal-abuse-210ae2be2a5
Detection Testing
Test Type | Status | Dataset | Source | Sourcetype |
---|---|---|---|---|
Validation | ✅ Passing | N/A | N/A | N/A |
Unit | ✅ Passing | Dataset | o365 |
o365:management:activity |
Integration | ✅ Passing | Dataset | o365 |
o365:management:activity |
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: 2