ID | Technique | Tactic |
---|---|---|
T1098.003 | Additional Cloud Roles | Persistence |
Detection: O365 Admin Consent Bypassed by Service Principal
Description
The following analytic identifies instances where a service principal in Office 365 Azure Active Directory assigns app roles without standard admin consent. It leverages o365_management_activity
logs, specifically focusing on the 'Add app role assignment to service principal' operation. This activity is significant for SOCs as it may indicate a bypass of critical administrative controls, potentially leading to unauthorized access or privilege escalation. If confirmed malicious, this could allow an attacker to misuse automated processes to assign sensitive permissions, compromising the security of the environment.
Search
1`o365_management_activity` Workload=AzureActiveDirectory Operation="Add app role assignment to service principal."
2| eval len=mvcount('Actor{}.ID')
3| eval userType = mvindex('Actor{}.ID',len-1)
4| eval roleId = mvindex('ModifiedProperties{}.NewValue', 0)
5| eval roleValue = mvindex('ModifiedProperties{}.NewValue', 1)
6| eval roleDescription = mvindex('ModifiedProperties{}.NewValue', 2)
7| eval dest_user = mvindex('Target{}.ID', 0)
8| search userType = "ServicePrincipal"
9| eval src_user = user
10| stats count earliest(_time) as firstTime latest(_time) as lastTime by src_user dest_user roleId roleValue roleDescription
11| `security_content_ctime(firstTime)`
12| `security_content_ctime(lastTime)`
13| `o365_admin_consent_bypassed_by_service_principal_filter`
Data Source
Name | Platform | Sourcetype | Source |
---|---|---|---|
O365 Add app role assignment to service principal. | N/A | 'o365:management:activity' |
'o365' |
Macros Used
Name | Value |
---|---|
o365_management_activity | sourcetype=o365:management:activity |
o365_admin_consent_bypassed_by_service_principal_filter | search * |
o365_admin_consent_bypassed_by_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
Service Principals are sometimes configured to legitimately bypass the consent process for purposes of automation. Filter as needed.
Associated Analytic Story
Risk Based Analytics (RBA)
Risk Message | Risk Score | Impact | Confidence |
---|---|---|---|
Service principal $src_user$ bypassed the admin consent process and granted permissions to $dest_user$ | 54 | 90 | 60 |
References
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: 3