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Description

This detection is tailored to spot occurrences where a single user, rather than a service principal, creates more than three unique OAuth applications within a 10-minute window in the Office 365 environment. Utilizing O365 logs from the Unified Audit Log, it focuses on the 'Add service principal' operation in Azure Active Directory. The query segments events into 10-minute intervals, exclusively monitoring user activities. It calculates the number of distinct OAuth applications initiated by each user, providing SOC teams with essential data for identifying potential security threats. Such activity could suggest that a user account is either compromised or engaged in unauthorized activities, potentially setting the stage for broader network infiltration or privilege escalation. It's important for security teams to adjust the threshold of three applications to fit their operational context.

  • Type: Anomaly

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-02-07
  • Author: Mauricio Velazco, Splunk
  • ID: a34e65d0-54de-4b02-9db8-5a04522067f6

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1136.003 Cloud Account Persistence
Kill Chain Phase
  • Installation
NIST
  • DE.AE
CIS20
  • CIS 10
CVE 


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`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 = "User" 
| eval displayName = object 
| stats count earliest(_time) as firstTime latest(_time) as lastTime values(displayName) as displayName dc(displayName) as unique_apps by src_user 
| where unique_apps > 3 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `o365_multiple_service_principals_created_by_user_filter`

Macros

The SPL above uses the following Macros:

:information_source: o365_multiple_service_principals_created_by_user_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Workload
  • Operation
  • Actor{}.ID
  • src_user
  • object

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.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
42.0 70 60 Multiple OAuth applications were created by $src_user$ in a short period of time

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 1