Azure AD Privileged Graph API Permission Assigned

Try in Splunk Security Cloud

Description

The following analytic detects the assignment of high-risk Graph API permissions in Azure AD, specifically Application.ReadWrite.All, AppRoleAssignment.ReadWrite.All, and RoleManagement.ReadWrite.Directory. It uses azure_monitor_aad data to scan AuditLogs for 'Update application' operations, identifying when these permissions are assigned. This activity is significant as it grants broad control over Azure AD, including application and directory settings. If confirmed malicious, it could lead to unauthorized modifications and potential security breaches, compromising the integrity and security of the Azure AD environment. Immediate investigation is required.

• Type: TTP

• Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

• Last Updated: 2024-05-11
• Author: Mauricio Velazco, Splunk
• ID: 5521f8c5-1aa3-473c-9eb7-853701924a06

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1003.002	Security Account Manager	Credential Access

Kill Chain Phase

• Exploitation

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

`azure_monitor_aad` category=AuditLogs operationName="Update application"  
| eval newvalue = mvindex('properties.targetResources{}.modifiedProperties{}.newValue',0) 
| spath input=newvalue  
| search "{}.RequiredAppPermissions{}.EntitlementId"="1bfefb4e-e0b5-418b-a88f-73c46d2cc8e9" OR "{}.RequiredAppPermissions{}.EntitlementId"="06b708a9-e830-4db3-a914-8e69da51d44f" OR "{}.RequiredAppPermissions{}.EntitlementId"="9e3f62cf-ca93-4989-b6ce-bf83c28f9fe8"  
| 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_privileged_graph_api_permission_assigned_filter`

Macros

The SPL above uses the following Macros:

• azure_monitor_aad
• security_content_ctime

azure_ad_privileged_graph_api_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
• category
• operationName
• properties.targetResources{}.modifiedProperties{}.newValue
• user
• object
• user_agent

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. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the AuditLog log category.

Known False Positives

Privileged Graph API permissions may be assigned for legitimate purposes. Filter as needed.

Associated Analytic Story

• Azure Active Directory Persistence
• NOBELIUM Group

RBA

Risk Score	Impact	Confidence	Message
54.0	90	60	User $user$ assigned privileged Graph API permissions to $object$

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://cloudbrothers.info/en/azure-attack-paths/
• https://github.com/mandiant/Mandiant-Azure-AD-Investigator/blob/master/MandiantAzureADInvestigator.json
• https://learn.microsoft.com/en-us/graph/permissions-reference
• https://www.microsoft.com/en-us/security/blog/2024/01/25/midnight-blizzard-guidance-for-responders-on-nation-state-attack/
• https://posts.specterops.io/azure-privilege-escalation-via-azure-api-permissions-abuse-74aee1006f48

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