Detection rules › Splunk

O365 Added Service Principal

Status
production
Severity
medium
Group by
aws::recipientAccountId, dest, signature, src, user, vendor_product
Author
Rod Soto, Splunk
Source
github.com/splunk/security_content

The following analytic detects the addition of new service principal accounts in O365 tenants. It leverages data from the o365_management_activity dataset, specifically monitoring for operations related to adding or creating service principals. This activity is significant because attackers can exploit service principals to gain unauthorized access and perform malicious actions within an organization's environment. If confirmed malicious, this could allow attackers to interact with APIs, access resources, and execute operations on behalf of the organization, potentially leading to data breaches or further compromise.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1136.003 Create Account: Cloud Account

Rule body splunk

name: O365 Added Service Principal
id: 1668812a-6047-11eb-ae93-0242ac130002
version: 13
creation_date: '2021-01-26'
modification_date: '2026-05-13'
author: Rod Soto, Splunk
status: production
type: TTP
description: The following analytic detects the addition of new service principal accounts in O365 tenants. It leverages data from the `o365_management_activity` dataset, specifically monitoring for operations related to adding or creating service principals. This activity is significant because attackers can exploit service principals to gain unauthorized access and perform malicious actions within an organization's environment. If confirmed malicious, this could allow attackers to interact with APIs, access resources, and execute operations on behalf of the organization, potentially leading to data breaches or further compromise.
data_source:
    - O365
search: |-
    `o365_management_activity` Workload=AzureActiveDirectory Operation="*Add service principal*" OR (Operation = "*principal*" AND action = "created")
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY signature dest user
           src vendor_account vendor_product
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `o365_added_service_principal_filter`
how_to_implement: You must install splunk Microsoft Office 365 add-on. This search works with o365:management:activity
known_false_positives: The creation of a new Federation is not necessarily malicious, however these events need to be followed closely, as it may indicate federated credential abuse or backdoor via federated identities at a different cloud provider.
references:
    - https://www.fireeye.com/content/dam/fireeye-www/blog/pdfs/wp-m-unc2452-2021-000343-01.pdf
    - https://www.cisa.gov/uscert/ncas/alerts/aa21-008a
    - https://www.splunk.com/en_us/blog/security/a-golden-saml-journey-solarwinds-continued.html
    - https://blog.sygnia.co/detection-and-hunting-of-golden-saml-attack?hsLang=en
drilldown_searches:
    - name: View the detection results for - "$user$"
      search: '%original_detection_search% | search  user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") | 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: User $user$ has created new service principal in AzureActiveDirectory
    entity:
        field: user
        type: user
        score: 50
analytic_story:
    - Office 365 Persistence Mechanisms
    - Cloud Federated Credential Abuse
    - NOBELIUM Group
asset_type: O365 Tenant
mitre_attack_id:
    - T1136.003
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: cloud
security_domain: threat
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1136.003/o365_added_service_principal/o365_add_service_principal.log
          sourcetype: o365:management:activity
          source: o365
      test_type: unit

Stages and Predicates

Stage 1: search

`o365_management_activity` Workload=AzureActiveDirectory Operation="*Add service principal*" OR (Operation = "*principal*" AND action = "created")

Stage 2: fillnull

| fillnull

Stage 3: stats

| stats count min(_time) as firstTime max(_time) as lastTime
    BY signature dest user
       src vendor_account vendor_product

Stage 4: search

| `security_content_ctime(firstTime)`

Stage 5: search

| `security_content_ctime(lastTime)`

Stage 6: search

| `o365_added_service_principal_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*"
  • "*principal*"
Workloadeq
  • AzureActiveDirectory
actioneq
  • "created"
sourcetypeeq
  • o365:management:activity