Azure Activity Logs: DNS Zone Write or Delete Operations

title: "Azure Activity Logs: DNS Zone Write or Delete Operations"
id: 962a58a3-fbc1-4adc-a4ab-ddc71afc49cf
status: test
description: This rule flags Azure Activity Log events where the operation name targets DNS zones with either a WRITE or DELETE action. Attackers or misusers may change or remove DNS zones to disrupt name resolution and affect service availability or redirection. The detection relies on Azure Activity Log telemetry capturing the DNS zone operation names, including the WRITE and DELETE suffixes.
references:
  - https://learn.microsoft.com/en-us/azure/role-based-access-control/resource-provider-operations#microsoftkubernetes
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/azure/activity_logs/azure_dns_zone_modified_or_deleted.yml
author: Austin Songer @austinsonger, Huntrule Team
date: 2021-08-08
modified: 2022-08-23
tags:
  - attack.impact
  - attack.t1565.001
logsource:
  product: azure
  service: activitylogs
detection:
  selection:
    operationName|startswith: MICROSOFT.NETWORK/DNSZONES
    operationName|endswith:
      - /WRITE
      - /DELETE
  condition: selection
falsepositives:
  - DNS zone modified and deleted may be performed by a system administrator. Verify whether the user identity, user agent, and/or hostname should be making changes in your environment.
  - DNS zone modification from unfamiliar users should be investigated. If known behavior is causing false positives, it can be exempted from the rule.
level: medium
license: DRL-1.1
related:
  - id: af6925b0-8826-47f1-9324-337507a0babd
    type: derived