Google Cloud VPN Tunnel Insert or Delete via Audit Logs

title: Google Cloud VPN Tunnel Insert or Delete via Audit Logs
id: 3ccb2306-4730-4beb-8ae7-2441792abd19
status: test
description: This rule flags Google Cloud audit log events where a VPN Tunnel is created or removed. Attackers or insiders may modify network connectivity by adding or deleting VPN tunnels to enable unauthorized access or disrupt legitimate routing. It relies on GCP audit telemetry for method names corresponding to VPN tunnel insert and delete operations.
references:
  - https://any-api.com/googleapis_com/compute/docs/vpnTunnels
  - https://github.com/SigmaHQ/sigma/blob/master/rules/cloud/gcp/audit/gcp_vpn_tunnel_modified_or_deleted.yml
author: Austin Songer @austinsonger, Huntrule Team
date: 2021-08-16
modified: 2022-10-09
tags:
  - attack.impact
logsource:
  product: gcp
  service: gcp.audit
detection:
  selection:
    gcp.audit.method_name:
      - compute.vpnTunnels.insert
      - compute.vpnTunnels.delete
  condition: selection
falsepositives:
  - VPN Tunnel 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.
  - VPN Tunnel 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: 99980a85-3a61-43d3-ac0f-b68d6b4797b1
    type: derived