Azure Runbook Webhook Created

Name:Azure Runbook Webhook Created
id:e98944a9-92e4-443c-81b8-a322e33ce75a
version:15
date:None
author:Mauricio Velazco, Brian Serocki, Splunk
status:production
type:TTP
Description:The following analytic detects the creation of a new Automation Runbook Webhook within an Azure tenant. It leverages Azure Audit events, specifically the "Create or Update an Azure Automation webhook" operation, to identify this activity. This behavior is significant because Webhooks can trigger Automation Runbooks via unauthenticated URLs exposed to the Internet, posing a security risk. If confirmed malicious, an attacker could use this to execute code, create users, or maintain persistence within the environment, potentially leading to unauthorized access and control over Azure resources.
Data_source:

• -Azure Audit Create or Update an Azure Automation webhook

search:`azure_audit` operationName.value="Microsoft.Automation/automationAccounts/webhooks/write" 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 values(dest) as dest
BY object user, src_ip,
resourceGroupName, object_path

| `security_content_ctime(firstTime)`

| `security_content_ctime(lastTime)`

| `azure_runbook_webhook_created_filter`

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 Runbook Webhooks. Filter as needed.
References:
  -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/automation-webhooks?tabs=portal
  -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/T1078/004/
drilldown_searches:
 name:'View the detection results for - "$user$"'
 search:'%original_detection_search% | search user = "$user$"'
 earliest_offset:'$info_min_time$'
 latest_offset:'$info_max_time$'
 name:'View risk events for the last 7 days for - "$user$"'
 search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
 earliest_offset:'7d'
 latest_offset:'0'
analytic_story:['Azure Active Directory Persistence']

asset_type:Azure Tenant

mitre_attack_id:['T1078.004']

product:['Splunk Enterprise', 'Splunk Enterprise Security', 'Splunk Cloud']

category:cloud

security_domain:threat

tags:

tests:
 name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1078.004/azure_runbook_webhook/azure-activity.log
  source: mscs:azure:audit
  sourcetype: mscs:azure:audit
 test_type:'unit'
manual_test:None