Azure AD Multiple Service Principals Created by SP
Description
The following analytic detects when a single service principal in Azure AD creates more than three unique OAuth applications within a 10-minute span. It leverages Azure AD audit logs, specifically monitoring the 'Add service principal' operation initiated by service principals. This behavior is significant as it may indicate an attacker using a compromised or malicious service principal to rapidly establish multiple service principals, potentially staging an attack. If confirmed malicious, this activity could facilitate network infiltration or expansion, allowing the attacker to gain unauthorized access and persist within the environment.
Query · spl
`azure_monitor_aad` operationName="Add service principal" properties.initiatedBy.app.appId=*
| rename properties.* as *
| bucket span=10m _time
| rename targetResources{}.displayName as displayName
| rename targetResources{}.type as type
| rename initiatedBy.app.displayName as src_user
| rename userAgent as user_agent
| fillnull
| stats count min(_time) as firstTime max(_time) as lastTime dc(displayName) as unique_apps values(displayName) as displayName values(dest) as dest values(src) as src values(user) as user values(user_agent) as user_agent
BY src_user vendor_account vendor_product
signature
| where unique_apps > 3
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `azure_ad_multiple_service_principals_created_by_sp_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 through an EventHub. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the AuditLogs log category.
Known false positives
- Certain users or applications may create multiple service principals in a short period of time for legitimate purposes. Filter as needed.
Analyst notes
Known false positives: Certain users or applications may create multiple service principals in a short period of time for legitimate purposes. Filter as needed.