Detection: Azure AD Multiple Service Principals Created by User

Updated Date: 2024-09-30 ID: 32880707-f512-414e-bd7f-204c0c85b758 Author: Mauricio Velazco, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

The following analytic identifies instances where a single user creates more than three unique OAuth applications within a 10-minute timeframe in Azure AD. It detects this activity by monitoring the 'Add service principal' operation and aggregating data in 10-minute intervals. This behavior is significant as it may indicate an adversary rapidly creating multiple service principals to stage an attack or expand their foothold within the network. If confirmed malicious, this activity could allow attackers to establish persistence, escalate privileges, or access sensitive information within the Azure environment.

1`azure_monitor_aad` operationName="Add service principal" properties.initiatedBy.user.id=* 
2| rename properties.* as * 
3| bucket span=10m _time 
4| rename targetResources{}.displayName as displayName 
5| stats min(_time) as firstTime max(_time) as lastTime values(displayName) as displayName dc(displayName) as unique_apps by src_user 
6| where unique_apps > 3 
7| `security_content_ctime(firstTime)` 
8| `security_content_ctime(lastTime)` 
9| `azure_ad_multiple_service_principals_created_by_user_filter`

Data Source

Name Platform Sourcetype Source
Azure Active Directory Add service principal Azure icon Azure 'azure:monitor:aad' 'Azure AD'

Macros Used

Name Value
azure_monitor_aad sourcetype=azure:monitor:aad
azure_ad_multiple_service_principals_created_by_user_filter search *
azure_ad_multiple_service_principals_created_by_user_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1136.003 Cloud Account Persistence
KillChainPhase.INSTALLATION
NistCategory.DE_AE
Cis18Value.CIS_10
APT29
LAPSUS$

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Risk Event True
This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

Implementation

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 through an EventHub. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the AuditLogs log category.

Known False Positives

Certain users or applications may create multiple service principals in a short period of time for legitimate purposes. Filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
Multiple OAuth applications were created by $src_user$ in a short period of time 42 70 60
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset Azure AD azure:monitor:aad
Integration ✅ Passing Dataset Azure AD azure:monitor:aad

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: GitHub | Version: 4