Azure AD Admin Consent Bypassed by Service Principal
Description
The following analytic identifies instances where a service principal in Azure Active Directory assigns app roles without standard admin consent. It uses Entra ID logs from the azure_monitor_aad data source, focusing on the "Add app role assignment to service principal" operation. This detection is significant as it highlights potential bypasses of critical administrative consent processes, which could lead to unauthorized privileges being granted. If confirmed malicious, this activity could allow attackers to exploit automation to assign sensitive permissions without proper oversight, potentially compromising the security of the Azure AD environment.
Query · spl
`azure_monitor_aad` (operationName="Add app role assignment to service principal" OR operationName="Add member to role*") src_user_type=servicePrincipal | rename properties.* as * | eval roleId = mvindex('targetResources{}.modifiedProperties{}.newValue',0) | eval roleValue = mvindex('targetResources{}.modifiedProperties{}.newValue',1) | eval roleDescription = mvindex('targetResources{}.modifiedProperties{}.newValue',2) | eval user_id = mvindex('targetResources{}.id', 0), user=coalesce(user,mvindex('targetResources{}.displayName',0)) | rename initiatedBy.app.displayName as src_user, userAgent as user_agent | fillnull | stats count min(_time) as firstTime max(_time) as lastTime by dest user src vendor_account vendor_product src_user user_id roleId roleValue roleDescription user_agent signature | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `azure_ad_admin_consent_bypassed_by_service_principal_filter`
Implementation guide
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
- Service Principals are sometimes configured to legitimately bypass the consent process for purposes of automation. Filter as needed.
Analyst notes
Known false positives: Service Principals are sometimes configured to legitimately bypass the consent process for purposes of automation. Filter as needed.