Azure Automation Runbook Created

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Description

The following analytic detects the creation of a new Azure Automation Runbook within an Azure tenant. It leverages Azure Audit events, specifically the Azure Activity log category, to identify when a new Runbook is created or updated. This activity is significant because adversaries with privileged access can use Runbooks to maintain persistence, escalate privileges, or execute malicious code. If confirmed malicious, this could lead to unauthorized actions such as creating Global Administrators, executing code on VMs, and compromising the entire Azure environment.

• Type: TTP

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

• Last Updated: 2024-05-11
• Author: Mauricio Velazco, Splunk
• ID: 178d696d-6dc6-4ee8-9d25-93fee34eaf5b

Annotations

ATT&CK

ATT&CK

ID	Technique	Tactic
T1136	Create Account	Persistence

T1136.003

Cloud Account

Persistence

Kill Chain Phase

• Installation

NIST

• DE.CM

CIS20

• CIS 10

CVE

Search

 `azure_audit` operationName.localizedValue="Create or Update an Azure Automation Runbook" object!=AzureAutomationTutorial* status.value=Succeeded 
| dedup object 
| rename claims.ipaddr as src_ip 
| rename caller as user 
| stats count min(_time) as firstTime max(_time) as lastTime by object user, src_ip, resourceGroupName, object_path 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `azure_automation_runbook_created_filter`

Macros

The SPL above uses the following Macros:

• azure_audit
• security_content_ctime

azure_automation_runbook_created_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.localizedValue
• status.value
• object
• caller
• claims.ipaddr
• resourceGroupName
• object_path

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 Audit events into your Splunk environment. Specifically, this analytic leverages the Azure Activity log category.

Known False Positives

Administrators may legitimately create Azure Automation Runbooks. Filter as needed.

Associated Analytic Story

• Azure Active Directory Persistence

RBA

Risk Score	Impact	Confidence	Message
63.0	70	90	A new Azure Automation Runbook $object$ was created by $user$

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

• https://docs.microsoft.com/en-us/azure/automation/overview
• https://docs.microsoft.com/en-us/azure/automation/automation-runbook-types
• https://docs.microsoft.com/en-us/azure/automation/manage-runbooks
• https://www.inversecos.com/2021/12/how-to-detect-malicious-azure.html
• https://www.netspi.com/blog/technical/cloud-penetration-testing/maintaining-azure-persistence-via-automation-accounts/
• https://microsoft.github.io/Azure-Threat-Research-Matrix/Persistence/AZT503/AZT503-3/
• https://attack.mitre.org/techniques/T1136/003/

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