Threat logs

Threat logs let you audit, verify, and analyze the threats detected in your network.

When Cloud Next Generation Firewall detects a threat on the traffic being monitored for Layer 7 inspection, it generates a log entry in the originating project with the details of the threat. To view and examine the threat logs, in the Logs Explorer, search for the log networksecurity.googleapis.com/firewall_threat. You can also view these threat logs on the Threats page.

This page explains the format and structure of the threat logs that are generated when a threat is detected.

Threat log format

Cloud NGFW creates a log record entry in Cloud Logging for each threat detected on the monitored traffic to or from a virtual machine (VM) instance in a specific zone. Log records are included in the JSON payload field of a LogEntry.

Some log fields are in a multiple-field format, with more than one piece of data in a given field. For example, the connection field is of the Connection format, which contains the server IP address and port, the client IP address and port, and the protocol number in a single field.

The following table describes the format of the threat log fields.

Field Type Description
connection Connection A 5-tuple that describes the connection parameters associated with the traffic where the threat is detected.
action string The action performed on the packet where the threat is detected. This action can either be the default action or the override action specified in the security profile.
threatDetails ThreatDetails The details of the threat detected.
securityProfileGroupDetails SecurityProfileGroupDetails The details of the security profile group applied to the intercepted traffic.
interceptVpc VpcDetails The details of the Virtual Private Cloud (VPC) network associated with the VM instance or the load balancer where the threat is detected.

For both VM instances and load balancer forwarding rules, the project that owns the VPC network serves as the logging project.

interceptInstance InterceptInstance The details of the VM instance where the threat is detected.
interceptLoadBalancer LoadBalancingDetails The details of the load balancer where the threat is detected and the firewall rule is applied.

Connection field format

The following table describes the format of the Connection field.

Field Type Description
clientIp string The client IP address. If the client is a Compute Engine VM, clientIp is either the primary internal IP address or an address in an alias IP range of the VM's network interface. The external IP address is not shown. The logs show the IP address of the VM instance as observed on the packet header, similar to the TCP dump on the VM instance.
clientPort