Detection rules › Splunk

O365 Privileged Role Assigned

Status
production
Severity
medium
Group by
aws::recipientAccountId, category, dest, object_id, object_name, result, signature, src, user, vendor_product
Author
Steven Dick
Source
github.com/splunk/security_content

The following analytic identifies the assignment of sensitive and privileged Azure Active Directory roles to an Azure AD user. Adversaries and red teams alike may assign these roles to a compromised account to establish Persistence in an Azure AD environment. This detection leverages the O365 Universal Audit Log data source.

MITRE ATT&CK coverage

Rules detecting the same action

Other rules on this platform that filter on the same API call or operation.

Rule body splunk

name: O365 Privileged Role Assigned
id: db435700-4ddc-4c23-892e-49e7525d7d39
version: 11
creation_date: '2024-04-13'
modification_date: '2026-05-13'
author: Steven Dick
status: production
type: TTP
description: The following analytic identifies the assignment of sensitive and privileged Azure Active Directory roles to an Azure AD user. Adversaries and red teams alike may assign these roles to a compromised account to establish Persistence in an Azure AD environment. This detection leverages the O365 Universal Audit Log data source.
data_source:
    - Office 365 Universal Audit Log
search: "`o365_management_activity` Workload=AzureActiveDirectory Operation IN (\"Add member to role.\",\"Add eligible member to role.\") | eval user = ObjectId, src_user = case(match(mvindex('Actor{}.ID',-1),\"User\"),mvindex('Actor{}.ID',0),match(mvindex('Actor{}.ID',-1),\"ServicePrincipal\"),mvindex('Actor{}.ID',3),true(),mvindex('Actor{}.ID',0)), object_name = mvindex('ModifiedProperties{}.NewValue', mvfind('ModifiedProperties{}.Name',\"Role\\.DisplayName\")), object_id = mvindex('ModifiedProperties{}.NewValue', mvfind('ModifiedProperties{}.Name',\"Role\\.TemplateId\")), signature = Operation, result = ResultStatus, category = mvindex('Target{}.ID',2) | fillnull | stats count, min(_time) as firstTime, max(_time) as lastTime by src_user, src, user, category, result, object_name, object_id, signature, vendor_account, vendor_product, dest | lookup privileged_azure_ad_roles azuretemplateid as object_id OUTPUT isprvilegedadrole | search isprvilegedadrole=\"TRUE\" category=\"User\" | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `o365_privileged_role_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: Administrators will legitimately assign the privileged roles users as part of administrative tasks. Microsoft Privileged Identity Management (PIM) may cause false positives / less accurate alerting.
references:
    - https://attack.mitre.org/techniques/T1098/003/
    - https://learn.microsoft.com/en-us/azure/active-directory/roles/permissions-reference
    - https://learn.microsoft.com/en-us/microsoft-365/admin/add-users/about-exchange-online-admin-role?view=o365-worldwide
drilldown_searches:
    - name: View the detection results for - "$user$" and "$src_user$"
      search: '%original_detection_search% | search  user = "$user$" src_user = "$src_user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$" and "$src_user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$src_user$") | 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: A privileged Azure AD role [$object_name$] was assigned to user $user$ by $src_user$
    entity:
        field: src_user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: user
          type: user
          score: 50
          message: A privileged Azure AD role [$object_name$] was assigned to user $user$ by $src_user$
analytic_story:
    - Azure Active Directory Persistence
    - Scattered Lapsus$ Hunters
asset_type: O365 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/o365_azure_workload_events/o365_azure_workload_events.log
          sourcetype: o365:management:activity
          source: o365
      test_type: unit

Stages and Predicates

Stage 1: search

`o365_management_activity` Workload=AzureActiveDirectory Operation IN ("Add member to role.","Add eligible member to role.")

Stage 2: eval

| eval user = ObjectId, src_user = case(match(mvindex('Actor{}.ID',-1),"User"),mvindex('Actor{}.ID',0),match(mvindex('Actor{}.ID',-1),"ServicePrincipal"),mvindex('Actor{}.ID',3),true(),mvindex('Actor{}.ID',0)), object_name = mvindex('ModifiedProperties{}.NewValue', mvfind('ModifiedProperties{}.Name',"Role\.DisplayName")), object_id = mvindex('ModifiedProperties{}.NewValue', mvfind('ModifiedProperties{}.Name',"Role\.TemplateId")), signature = Operation, result = ResultStatus, category = mvindex('Target{}.ID',2)
src_user =
ifmatch(mvindex('Actor{}.ID', -1), "User")mvindex('Actor{}.ID', 0)
elifmatch(mvindex('Actor{}.ID', -1), "ServicePrincipal")mvindex('Actor{}.ID', 3)
elsemvindex('Actor{}.ID', 0)

Stage 3: fillnull

| fillnull

Stage 4: stats

| stats count, min(_time) as firstTime, max(_time) as lastTime by src_user, src, user, category, result, object_name, object_id, signature, vendor_account, vendor_product, dest

Stage 5: lookup

| lookup privileged_azure_ad_roles azuretemplateid as object_id OUTPUT isprvilegedadrole
Lookup table
privileged_azure_ad_roles
Key field
azuretemplateid as object_id
Output columns
['isprvilegedadrole', 'isprvilegedadrole']

Stage 6: search

| search isprvilegedadrole="TRUE" category="User"

Stage 7: search

| `security_content_ctime(firstTime)`

Stage 8: search

| `security_content_ctime(lastTime)`

Stage 9: search

| `o365_privileged_role_assigned_filter`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Operationin
  • "Add eligible member to role."
  • "Add member to role."
Workloadeq
  • AzureActiveDirectory
categoryeq
  • "User"
isprvilegedadroleeq
  • "TRUE"
sourcetypeeq
  • o365:management:activity