Detection rules › Splunk

O365 Multiple Service Principals Created by SP

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

The following analytic identifies instances where a single service principal creates more than three unique OAuth applications within a 10-minute timeframe. It leverages O365 logs from the Unified Audit Log, focusing on the 'Add service principal' operation in the Office 365 Azure Active Directory environment. This activity is significant as it may indicate a compromised or malicious service principal attempting to expand control or access within the network. If confirmed malicious, this could lead to unauthorized access and potential lateral movement within the environment, posing a significant security risk.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1136.003 Create Account: Cloud Account

Rules detecting the same action

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

Rule body splunk

name: O365 Multiple Service Principals Created by SP
id: ef4c3f20-d1ad-4ad1-a3f4-d5f391c005fe
version: 9
creation_date: '2024-02-14'
modification_date: '2026-05-13'
author: Mauricio Velazco, Splunk
status: production
type: Anomaly
description: The following analytic identifies instances where a single service principal creates more than three unique OAuth applications within a 10-minute timeframe. It leverages O365 logs from the Unified Audit Log, focusing on the 'Add service principal' operation in the Office 365 Azure Active Directory environment. This activity is significant as it may indicate a compromised or malicious service principal attempting to expand control or access within the network. If confirmed malicious, this could lead to unauthorized access and potential lateral movement within the environment, posing a significant security risk.
data_source:
    - O365 Add service principal.
search: "`o365_management_activity` Workload=AzureActiveDirectory Operation=\"Add service principal.\" | bucket span=10m _time | eval len=mvcount('Actor{}.ID') | eval userType = mvindex('Actor{}.ID',len-1) | search userType = \"ServicePrincipal\" | eval displayName = object | fillnull | stats count earliest(_time) as firstTime latest(_time) as lastTime values(displayName) as displayName dc(displayName) as unique_apps values(user) as user values(src) as src by src_user vendor_account vendor_product dest signature | where unique_apps > 3 | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `o365_multiple_service_principals_created_by_sp_filter`"
how_to_implement: You must install the Splunk Microsoft Office 365 Add-on and ingest Office 365 management activity events.
known_false_positives: Certain users or applications may create multiple service principals in a short period of time for legitimate purposes. Filter as needed.
references:
    - https://attack.mitre.org/techniques/T1136/003/
    - https://www.microsoft.com/en-us/security/blog/2024/01/25/midnight-blizzard-guidance-for-responders-on-nation-state-attack/
drilldown_searches:
    - name: View the detection results for - "$src_user$"
      search: '%original_detection_search% | search  src_user = "$src_user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$src_user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$src_user$") | 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"
intermediate_findings:
    entities:
        - field: src_user
          type: user
          score: 20
          message: Multiple OAuth applications were created by $src_user$ in a short period of time
analytic_story:
    - Office 365 Persistence Mechanisms
    - NOBELIUM Group
asset_type: O365 Tenant
mitre_attack_id:
    - T1136.003
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/T1136.003/o365_multiple_service_principals_created/o365_multiple_service_principals_created.log
          source: o365
          sourcetype: o365:management:activity
      test_type: unit

Stages and Predicates

Stage 1: search

`o365_management_activity` Workload=AzureActiveDirectory Operation="Add service principal."

Stage 2: bucket

| bucket span=10m _time

Stage 3: eval

| eval len=mvcount('Actor{}.ID')

Stage 4: eval

| eval userType = mvindex('Actor{}.ID',len-1)

Stage 5: search

| search userType = "ServicePrincipal"

Stage 6: eval

| eval displayName = object

Stage 7: fillnull

| fillnull

Stage 8: stats

| stats count earliest(_time) as firstTime latest(_time) as lastTime values(displayName) as displayName dc(displayName) as unique_apps values(user) as user values(src) as src by src_user vendor_account vendor_product dest signature

Stage 9: where

| where unique_apps > 3

Stage 10: search

| `security_content_ctime(firstTime)`

Stage 11: search

| `security_content_ctime(lastTime)`

Stage 12: search

| `o365_multiple_service_principals_created_by_sp_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
Operationeq
  • "Add service principal."
Workloadeq
  • AzureActiveDirectory
sourcetypeeq
  • o365:management:activity
unique_appsgt
  • 3
userTypeeq
  • "ServicePrincipal"