Detection: Azure AD Service Principal New Client Credentials

Updated Date: 2024-05-11 ID: e3adc0d3-9e4b-4b5d-b662-12cec1adff2a Author: Mauricio Velazco, Gowthamaraj Rajendran, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic detects the addition of new credentials to Service Principals and Applications in Azure AD. It leverages Azure AD AuditLogs, specifically monitoring the "Update application*Certificates and secrets management" operation. This activity is significant as it may indicate an adversary attempting to maintain persistent access or escalate privileges within the Azure environment. If confirmed malicious, attackers could use these new credentials to log in as the service principal, potentially compromising sensitive accounts and resources, leading to unauthorized access and control over the Azure environment.

1 `azure_monitor_aad`  category=AuditLogs operationName="Update application*Certificates and secrets management " 
2| rename properties.* as * 
3| rename  targetResources{}.* as * 
4| stats count min(_time) as firstTime max(_time) as lastTime values(displayName) as displayName by user, modifiedProperties{}.newValue, src_ip 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `azure_ad_service_principal_new_client_credentials_filter`

Data Source

Name Platform Sourcetype Source Supported App
Azure Active Directory Azure icon Azure 'azure:monitor:aad' 'Azure AD' N/A

Macros Used

Name Value
azure_monitor_aad sourcetype=azure:monitor:aad
azure_ad_service_principal_new_client_credentials_filter search *
azure_ad_service_principal_new_client_credentials_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
T1098 Account Manipulation Persistence
T1098.001 Additional Cloud Credentials Privilege Escalation
KillChainPhase.EXPLOITAITON
KillChainPhase.INSTALLATION
NistCategory.DE_CM
Cis18Value.CIS_10
APT3
APT41
APT5
Dragonfly
FIN13
HAFNIUM
Kimsuky
Lazarus Group
Magic Hound

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 Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

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. This analytic was written to be used with the azure:monitor:aad sourcetype leveraging the Signin log category.

Known False Positives

Service Principal client credential modifications may be part of legitimate administrative operations. Filter as needed.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
New credentials added for Service Principal by $user$ 35 70 50
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: 3