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Description

The following analytic identifies a successful authentication event against an Azure AD tenant using PowerShell commandlets. This behavior is not common for regular, non administrative users. After compromising an account in Azure AD, attackers and red teams alike will perform enumeration and discovery techniques. One method of executing these techniques is leveraging the native PowerShell modules.

  • Type: TTP

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

  • Last Updated: 2023-12-20
  • Author: Mauricio Velazco, Gowthamaraj Rajendran, Splunk
  • ID: 62f10052-d7b3-4e48-b57b-56f8e3ac7ceb

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1586 Compromise Accounts Resource Development
T1586.003 Cloud Accounts Resource Development
T1078 Valid Accounts Defense Evasion, Persistence, Privilege Escalation, Initial Access
T1078.004 Cloud Accounts Defense Evasion, Persistence, Privilege Escalation, Initial Access
Kill Chain Phase
  • Weaponization
  • Exploitation
  • Installation
  • Delivery
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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 `azure_monitor_aad`  category=SignInLogs properties.authenticationDetails{}.succeeded=true properties.appDisplayName="Microsoft Azure PowerShell" 
| rename properties.*  as * 
| stats count min(_time) as firstTime max(_time) as lastTime values(user) as user by src_ip, appDisplayName, user_agent 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `azure_ad_successful_powershell_authentication_filter`

Macros

The SPL above uses the following Macros:

:information_source: azure_ad_successful_powershell_authentication_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
  • properties.appDisplayName
  • category
  • user
  • src_ip
  • properties.appDisplayName
  • properties.userAgent

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

Known False Positives

Administrative users will likely use PowerShell commandlets to troubleshoot and maintain the environment. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
54.0 60 90 Successful authentication for user $user$ using PowerShell.

: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: 2