Name:Azure AD FullAccessAsApp Permission Assigned id:ae286126-f2ad-421c-b240-4ea83bd1c43a version:3 date:2024-09-30 author:Mauricio Velazco, Splunk status:production type:TTP Description:The following analytic detects the assignment of the 'full_access_as_app' permission to an application within Office 365 Exchange Online. This is identified by the GUID 'dc890d15-9560-4a4c-9b7f-a736ec74ec40' and the ResourceAppId '00000002-0000-0ff1-ce00-000000000000'. The detection leverages the azure_monitor_aad data source, focusing on AuditLogs with the operation name 'Update application'. This activity is significant as it grants broad control over Office 365 operations, including full access to all mailboxes and the ability to send emails as any user. If malicious, this could lead to unauthorized access and data exfiltration. Data_source:
how_to_implement: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:The full_access_as_app API permission may be assigned to legitimate applications. Filter as needed. References: -https://msrc.microsoft.com/blog/2024/01/microsoft-actions-following-attack-by-nation-state-actor-midnight-blizzard/ -https://www.microsoft.com/en-us/security/blog/2024/01/25/midnight-blizzard-guidance-for-responders-on-nation-state-attack/ -https://attack.mitre.org/techniques/T1098/002/ drilldown_searches: name:'View the detection results for - "$user$"' search:'%original_detection_search% | search user = "$user$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$user$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") starthoursago=168 | 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:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'Azure Active Directory Persistence' - 'NOBELIUM Group' asset_type:Azure Active Directory confidence:60 impact:80 message:User $user$ assigned the full_access_as_app permission to the app registration $object$ mitre_attack_id: - 'T1098.002' - 'T1098.003' observable: name:'user' type:'User' - role: - 'Victim' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' required_fields: - '_time' risk_score:48 security_domain:threat
