O365 Service Principal Privilege Escalation

name: O365 Service Principal Privilege Escalation
id: b686d0bd-cca7-44ca-ae07-87f6465131d9
version: 9
creation_date: '2025-01-05'
modification_date: '2026-05-13'
author: Dean Luxton
status: production
type: TTP
description: This detection identifies when an Azure Service Principal elevates privileges by adding themself to a new app role assignment.
data_source:
    - O365 Add app role assignment grant to user.
search: >-
    `o365_management_activity` Operation="Add app role assignment to service principal." "Actor{}.ID"=ServicePrincipal ResultStatus=Success
    | spath path=ModifiedProperties{} output=targetResources
    | eval src="NA"
    | stats min(_time) as _time values(eval(mvfilter(match(targetResources, "AppRole.Value")))) as appRole, values(eval(mvfilter(match(targetResources, "ServicePrincipal.DisplayName")))) as targetServicePrincipal values(object) as targetAppContext values(user_agent) as user_agent values(user) as servicePrincipal values(UserId) as servicePrincipalId by Operation InterSystemsId tenant_id user dest src vendor_account vendor_product signature
    | spath input=appRole path=NewValue output=appRole
    | spath input=targetServicePrincipal path=NewValue output=targetServicePrincipal
    | where servicePrincipal=targetServicePrincipal
    | fillnull
    | stats earliest(_time) as firstTime latest(_time) as lastTime by servicePrincipal servicePrincipalId appRole targetAppContext user_agent tenant_id InterSystemsId user dest src vendor_account vendor_product signature
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `o365_service_principal_privilege_escalation_filter`
how_to_implement: The Splunk Add-on for Microsoft Office 365 add-on is required to ingest EntraID audit logs via the 365 API. See references for links for further details on how to onboard this log source.
known_false_positives: No false positives have been identified at this time.
references:
    - https://splunkbase.splunk.com/app/4055
    - https://github.com/mvelazc0/BadZure
    - https://www.splunk.com/en_us/blog/security/hunting-m365-invaders-navigating-the-shadows-of-midnight-blizzard.html
    - https://posts.specterops.io/microsoft-breach-what-happened-what-should-azure-admins-do-da2b7e674ebc
drilldown_searches:
    - name: View the detection results for - "$servicePrincipal$"
      search: '%original_detection_search% | search  servicePrincipal = "$servicePrincipal$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$servicePrincipal$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$servicePrincipal$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: Service Principal $servicePrincipal$ has elevated privileges by adding themself to app role $appRole$
    entity:
        field: servicePrincipal
        type: user
        score: 50
threat_objects:
    - field: user_agent
      type: http_user_agent
analytic_story:
    - Azure Active Directory Privilege Escalation
    - Office 365 Account Takeover
asset_type: Azure Tenant
mitre_attack_id:
    - T1098.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: identity
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1098.003/o365_spn_privesc/o365_spn_privesc.log
          sourcetype: o365:management:activity
          source: Office 365
      test_type: unit