Detection rules › Splunk

Azure Runbook Webhook Created

Status
production
Severity
medium
Group by
group.name, object_path, resourceGroupName, src_ip, user
Author
Mauricio Velazco, Brian Serocki, Splunk
Source
github.com/splunk/security_content

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.

Known false positives

  • Administrators may legitimately create Azure Runbook Webhooks. Filter as needed.

MITRE ATT&CK coverage

Telemetry coverage

Rule body

name: Azure Runbook Webhook Created
id: e98944a9-92e4-443c-81b8-a322e33ce75a
version: 15
creation_date: '2022-08-23'
modification_date: '2026-05-13'
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/
finding:
    title: A new Azure Runbook Webhook $object$ was created by $user$
    entity:
        field: user
        type: user
        score: 50
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

Stages and Predicates

Stage 1: search

`azure_audit` operationName.value="Microsoft.Automation/automationAccounts/webhooks/write" status.value=Succeeded

Stage 2: dedup

| dedup object

Stage 3: rename

| rename claims.ipaddr as src_ip

Stage 4: rename

| rename caller as user

Stage 5: stats

| stats count min(_time) as firstTime max(_time) as lastTime values(dest) as dest
    BY object user, src_ip,
       resourceGroupName, object_path

Stage 6: search

| `security_content_ctime(firstTime)`

Stage 7: search

| `security_content_ctime(lastTime)`

Stage 8: search

| `azure_runbook_webhook_created_filter`

Indicators

These rows show field, operator, and value matches.