Detection rules › Splunk

O365 Privileged Graph API Permission Assigned

Status
production
Severity
medium
Group by
aws::recipientAccountId, aws::userAgent, dest, group.name, signature, src, user, vendor_product
Author
Mauricio Velazco, Splunk
Source
github.com/splunk/security_content

The following analytic detects the assignment of critical Graph API permissions in Azure AD using the O365 Unified Audit Log. It focuses on permissions such as Application.ReadWrite.All, AppRoleAssignment.ReadWrite.All, and RoleManagement.ReadWrite.Directory. The detection method leverages Azure Active Directory workload events, specifically 'Update application' operations. This activity is significant as these permissions provide extensive control over Azure AD settings, posing a high risk if misused. If confirmed malicious, this could allow unauthorized modifications, leading to potential data breaches or privilege escalation. Immediate investigation is crucial.

Known false positives

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

MITRE ATT&CK coverage

Telemetry coverage

PlatformRecord / event type
Microsoft 365Update application.

Rules detecting the same action

These rules filter on the same operation.

Rule body

name: O365 Privileged Graph API Permission Assigned
id: 868f3131-d5e1-4bf1-af5b-9b0fbaaaedbb
version: 9
creation_date: '2024-02-14'
modification_date: '2026-05-13'
author: Mauricio Velazco, Splunk
status: production
type: TTP
description: The following analytic detects the assignment of critical Graph API permissions in Azure AD using the O365 Unified Audit Log. It focuses on permissions such as Application.ReadWrite.All, AppRoleAssignment.ReadWrite.All, and RoleManagement.ReadWrite.Directory. The detection method leverages Azure Active Directory workload events, specifically 'Update application' operations. This activity is significant as these permissions provide extensive control over Azure AD settings, posing a high risk if misused. If confirmed malicious, this could allow unauthorized modifications, leading to potential data breaches or privilege escalation. Immediate investigation is crucial.
data_source:
    - O365 Update application.
search: "`o365_management_activity` Workload=AzureActiveDirectory Operation=\"Update application.\" | eval newvalue = mvindex('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' | fillnull | stats count earliest(_time) as firstTime latest(_time) as lastTime values(Permissions) by user src object user_agent signature vendor_account vendor_product dest | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `o365_privileged_graph_api_permission_assigned_filter`"
how_to_implement: You must install the Splunk Microsoft Office 365 Add-on and ingest Office 365 management activity events.
known_false_positives: Privileged Graph API permissions may be assigned for legitimate purposes. Filter as needed.
references:
    - 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
finding:
    title: User $user$ assigned privileged Graph API permissions to $object$
    entity:
        field: user
        type: user
        score: 50
analytic_story:
    - Office 365 Persistence Mechanisms
    - NOBELIUM Group
asset_type: O365 Tenant
mitre_attack_id:
    - T1003.002
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: identity

Stages and Predicates

Stage 1: search

`o365_management_activity` Workload=AzureActiveDirectory Operation="Update application."

Stage 2: eval

| eval newvalue = mvindex('ModifiedProperties{}.NewValue',0)

Stage 3: spath

| spath input=newvalue

Stage 4: search

| search "{}.RequiredAppPermissions{}.EntitlementId"="1bfefb4e-e0b5-418b-a88f-73c46d2cc8e9" OR "{}.RequiredAppPermissions{}.EntitlementId"="06b708a9-e830-4db3-a914-8e69da51d44f" OR "{}.RequiredAppPermissions{}.EntitlementId"="9e3f62cf-ca93-4989-b6ce-bf83c28f9fe8"

Stage 5: eval

| eval Permissions = '{}.RequiredAppPermissions{}.EntitlementId'

Stage 6: fillnull

| fillnull

Stage 7: stats

| stats count earliest(_time) as firstTime latest(_time) as lastTime values(Permissions) by user src object user_agent signature vendor_account vendor_product dest

Stage 8: search

| `security_content_ctime(firstTime)`

Stage 9: search

| `security_content_ctime(lastTime)`

Stage 10: search

| `o365_privileged_graph_api_permission_assigned_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Operationeq
  • "Update application."
field:"Operation" kind:eq
Workloadeq
  • AzureActiveDirectory
field:"Workload" kind:eq value:"AzureActiveDirectory"
sourcetypeeq
  • o365:management:activity
field:"sourcetype" kind:eq value:"o365:management:activity"
{}.RequiredAppPermissions{}.EntitlementIdeq
  • "06b708a9-e830-4db3-a914-8e69da51d44f"
  • "1bfefb4e-e0b5-418b-a88f-73c46d2cc8e9"
  • "9e3f62cf-ca93-4989-b6ce-bf83c28f9fe8"
field:"{}.RequiredAppPermissions{}.EntitlementId" kind:eq