Menu
Ensure That the Log Metric Filter and Alerts Exist for VPC Network Route Changes
The review-first prompt is selected by default. You can switch to a direct command or download a local copy.
Read SKILL.md and any companion files shown by SkillsMP before deciding whether to install.
Install with Codex or Claude Copy this prompt, paste it into Codex, Claude, or another assistant, and let it review the skill page and install it for you.
A direct command skips the review prompt. Inspect the source before running it.
npx skills add https://github.com/CyberStrikeus/CyberStrike --skill cis-gcp-foundations-2-8The command stays on one line. Scroll horizontally to inspect it before copying.
Prefer a local copy? Download the files currently available to SkillsMP.
Showing SKILL.md
macOS post-exploitation for credential harvesting, DTrace monitoring, TCC bypass, and stealth operations via native tools
Windows userland post-exploitation for credential harvesting, monitoring, AMSI/ETW bypass, and stealth operations
Kubernetes post-exploitation for container escape, secret extraction, RBAC abuse, and cluster persistence
Based on SOC occupation classification
| name | cis-gcp-foundations-2.8 |
| description | Ensure That the Log Metric Filter and Alerts Exist for VPC Network Route Changes |
| category | cis-gcp-foundations |
| version | 4.0.0 |
| author | cyberstrike-official |
| tags | ["cis","gcp","logging","monitoring","log-metrics","alerts","vpc","routes"] |
| cis_id | 2.8 |
| cis_benchmark | CIS Google Cloud Platform Foundation Benchmark v4.0.0 |
| tech_stack | ["gcp"] |
| cwe_ids | [] |
| chains_with | [] |
| prerequisites | [] |
| severity_boost | {} |
It is recommended that a metric filter and alarm be established for Virtual Private Cloud (VPC) network route changes.
Google Cloud Platform (GCP) routes define the paths network traffic takes from a VM instance to another destination. The other destination can be inside the organization VPC network (such as another VM) or outside of it. Every route consists of a destination and a next hop. Traffic whose destination IP is within the destination range is sent to the next hop for delivery.
Monitoring changes to route tables will help ensure that all VPC traffic flows through an expected path.
Enabling of logging may result in your project being charged for the additional logs usage. These charges could be significant depending on the size of the organization.
Ensure that the prescribed Log metric is present:
Logging/Logs-based Metrics by visiting https://console.cloud.google.com/logs/metrics.User-defined Metrics section, ensure that at least one metric <Log_Metric_Name> is present with the filter text:resource.type="gce_route"
AND (protoPayload.methodName:"compute.routes.delete"
OR protoPayload.methodName:"compute.routes.insert")
Ensure the prescribed alerting policy is present:
Alerting by visiting https://console.cloud.google.com/monitoring/alerting.Policies section, ensure that at least one alert policy exists for the log metric above. Clicking on the policy should show that it is configured with a condition. For example, Violates when: Any logging.googleapis.com/user/<Log Metric Name> stream is above a threshold of 0 for greater than zero(0) seconds means that the alert will trigger for any new owner change. Verify that the chosen alert thresholds make sense for the user's organization.Ensure that the prescribed log metric is present:
gcloud logging metrics list --format json
resource.type="gce_route"
AND (protoPayload.methodName:"compute.routes.delete"
OR protoPayload.methodName:"compute.routes.insert")
metricDescriptor.type for the identified metric, in the format logging.googleapis.com/user/<Log Metric Name>.Ensure that the prescribed alerting policy is present:
gcloud alpha monitoring policies list --format json
conditions.conditionThreshold.filter is set to metric.type=\"logging.googleapis.com/user/<Log Metric Name>\"enabled is set to trueA log metric filter exists matching the VPC network route changes filter, and at least one alert policy is configured and enabled for it.
Create the prescribed Log Metric:
Logging/Logs-based Metrics by visiting https://console.cloud.google.com/logs/metrics and click "CREATE METRIC".Filter Bar at the rightmost corner and select Convert to Advanced Filter.resource.type="gce_route"
AND (protoPayload.methodName:"compute.routes.delete"
OR protoPayload.methodName:"compute.routes.insert")
Submit Filter. Display logs appear based on the filter text entered by the user.Metric Editor menu on the right, fill out the name field. Set Units to 1 (default) and Type to Counter. This ensures that the log metric counts the number of log entries matching the advanced logs query.Create Metric.Create the prescribed alert policy:
User-defined Metrics at https://console.cloud.google.com/logs/metrics.Create alert from Metric. A new page displays.Save. Choose the alerting threshold and configuration that makes sense for the user's organization. For example, a threshold of zero(0) for the most recent value ensures that a notification is triggered for every owner change in the project:Set `Aggregator` to `Count`
Set `Configuration`:
- Condition: above
- Threshold: 0
- For: most recent value
Notifications.Save.Create the prescribed Log Metric:
gcloud logging metrics createCreate the prescribed alert policy:
gcloud alpha monitoring policies createBy default, no log metrics and alert policies are configured.
| Controls Version | Control | IG 1 | IG 2 | IG 3 |
|---|---|---|---|---|
| v8 | 8.2 Collect Audit Logs | x | x | x |
| v8 | 8.5 Collect Detailed Audit Logs | x | x | |
| v7 | 6.2 Activate audit logging | x | x | x |
| v7 | 6.3 Enable Detailed Logging | x | x |
Level 2