huntrule

Azure Virtual Network Device Modified or Deleted via Activity Logs

Alerts on Azure Activity Log operations that write or delete virtual network devices such as NICs, virtual appliances, hubs, and routers.

FreeReviewedSigma · Medium · v5
Product
azure
Service
activitylogs
Author
Austin Songer @austinsonger (SigmaHQ), DRL 1.1
Published
2021-08-08
Updated
2026-07-31
AnalysisDetection
title: Azure Virtual Network Device Modified or Deleted via Activity Logs
id: 0d583be0-d77b-45b6-b8f4-2ebf3c31a0c2
status: test
description: This rule flags Azure Activity Log events where a virtual network device is modified or deleted, including network interfaces, network virtual appliances, virtual hubs, and virtual routers. Such changes can disrupt connectivity, alter network behavior, or remove deployed infrastructure, making them high-impact even when performed via legitimate management actions. It relies on activity log telemetry with specific MICROSOFT.NETWORK operation names indicating WRITE, DELETE, or JOIN/ACTION for these resources.
references:
  - https://learn.microsoft.com/en-us/azure/role-based-access-control/resource-provider-operations
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/azure/activity_logs/azure_network_virtual_device_modified_or_deleted.yml
author: Austin Songer @austinsonger, Huntrule Team
date: 2021-08-08
modified: 2022-08-23
tags:
  - attack.impact
logsource:
  product: azure
  service: activitylogs
detection:
  selection:
    operationName:
      - MICROSOFT.NETWORK/NETWORKINTERFACES/TAPCONFIGURATIONS/WRITE
      - MICROSOFT.NETWORK/NETWORKINTERFACES/TAPCONFIGURATIONS/DELETE
      - MICROSOFT.NETWORK/NETWORKINTERFACES/WRITE
      - MICROSOFT.NETWORK/NETWORKINTERFACES/JOIN/ACTION
      - MICROSOFT.NETWORK/NETWORKINTERFACES/DELETE
      - MICROSOFT.NETWORK/NETWORKVIRTUALAPPLIANCES/DELETE
      - MICROSOFT.NETWORK/NETWORKVIRTUALAPPLIANCES/WRITE
      - MICROSOFT.NETWORK/VIRTUALHUBS/DELETE
      - MICROSOFT.NETWORK/VIRTUALHUBS/WRITE
      - MICROSOFT.NETWORK/VIRTUALROUTERS/WRITE
      - MICROSOFT.NETWORK/VIRTUALROUTERS/DELETE
  condition: selection
falsepositives:
  - Virtual Network Device being modified or 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.
  - Virtual Network Device modified or deleted 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: 15ef3fac-f0f0-4dc4-ada0-660aa72980b3
    type: derived