LoFP / firewall rules may be modified by system administrators. verify that the firewall configuration change was expected. exceptions can be added to this rule to filter expected behavior.

Techniques

• T1562

Sample rules

GCP Firewall Rule Modification

• source: elastic
• technicques:
  • T1562

Description

Identifies when a firewall rule is modified in Google Cloud Platform (GCP) for Virtual Private Cloud (VPC) or App Engine. These firewall rules can be modified to allow or deny connections to or from virtual machine (VM) instances or specific applications. An adversary may modify an existing firewall rule in order to weaken their target’s security controls and allow more permissive ingress or egress traffic flows for their benefit.

Detection logic

event.dataset:gcp.audit and event.action:(*.compute.firewalls.patch or google.appengine.*.Firewall.Update*Rule)