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Description

The following analytic detects an Azure AD user enabling a previously disabled account and resetting its password within 2 minutes. It uses Azure Active Directory events to identify this sequence of actions. This activity is significant because it may indicate an adversary with administrative access attempting to establish a backdoor identity within the Azure AD tenant. If confirmed malicious, this could allow the attacker to maintain persistent access, escalate privileges, and potentially exfiltrate sensitive information from the environment.

  • Type: TTP

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

  • Last Updated: 2024-05-26
  • Author: Mauricio Velazco, Gowthamaraj Rajendran, Splunk
  • ID: 1347b9e8-2daa-4a6f-be73-b421d3d9e268

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1098 Account Manipulation Persistence, Privilege Escalation
Kill Chain Phase
  • Installation
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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 `azure_monitor_aad`  (operationName="Enable account" OR operationName="Reset password (by admin)" OR operationName="Update user") 
| transaction user startsWith=(operationName="Enable account") endsWith=(operationName="Reset password (by admin)") maxspan=2m 
| rename properties.* as * 
| rename initiatedBy.user.userPrincipalName as initiatedBy 
| stats count min(_time) as firstTime max(_time) as lastTime values(operationName) as operationName values(initiatedBy) as initiatedBy by user, result 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `azure_ad_user_enabled_and_password_reset_filter`

Macros

The SPL above uses the following Macros:

:information_source: azure_ad_user_enabled_and_password_reset_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
  • operationName
  • user
  • properties.initiatedBy.user.userPrincipalName
  • properties.result

How To Implement

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 AuditLog log category.

Known False Positives

While not common, Administrators may enable accounts and reset their passwords for legitimate reasons. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
45.0 50 90 A user account, $user$, was enabled and its password reset within 2 minutes by $initiatedBy$

: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: 3