Azure AD FullAccessAsApp Permission Assigned
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.
- Type: TTP
-
Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
- Last Updated: 2024-05-12
- Author: Mauricio Velazco, Splunk
- ID: ae286126-f2ad-421c-b240-4ea83bd1c43a
Annotations
ATT&CK
Kill Chain Phase
- Installation
- Exploitation
NIST
- DE.CM
CIS20
- CIS 10
CVE
Search
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`azure_monitor_aad` category=AuditLogs operationName="Update application"
| eval newvalue = mvindex('properties.targetResources{}.modifiedProperties{}.newValue',0)
| spath input=newvalue
| search "{}.ResourceAppId"="00000002-0000-0ff1-ce00-000000000000" "{}.RequiredAppPermissions{}.EntitlementId"="dc890d15-9560-4a4c-9b7f-a736ec74ec40"
| eval Permissions = '{}.RequiredAppPermissions{}.EntitlementId'
| stats count earliest(_time) as firstTime latest(_time) as lastTime values(Permissions) by user, object, user_agent, operationName
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `azure_ad_fullaccessasapp_permission_assigned_filter`
Macros
The SPL above uses the following Macros:
azure_ad_fullaccessasapp_permission_assigned_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.
Required fields
List of fields required to use this analytic.
- _time
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.
Associated Analytic Story
RBA
Risk Score | Impact | Confidence | Message |
---|---|---|---|
48.0 | 80 | 60 | User $user$ assigned the full_access_as_app permission to the app registration $object$ |
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.
Reference
- 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/
Test Dataset
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 | version: 2