Creating an Alert for Nmap Scan Detection

The final step in this project is to set up an alert that will notify you if an Nmap scan is detected in your environment. In the Elastic SIEM, navigate to the Detections tab and click on “Create new rule.” You’ll create a custom query rule specifically designed to detect Nmap scan events.

In the rule creation interface, define your rule by setting the query to something like event.action: "nmap_scan". This query will trigger whenever the SIEM detects an event that matches the action “nmap_scan.” Name your rule appropriately (e.g., “Nmap Scan Detection”) and assign it a severity level. You can keep the default settings for how often the rule checks for new events or adjust it based on your needs.

Next, decide what action should be taken when this rule is triggered. Options include sending an email, posting a message to a Slack channel, or triggering a webhook that integrates with other security tools. Once you’ve configured the action, finalize the alert by clicking “Create and enable rule.”

Your alert is now active and will continuously monitor for Nmap scan events. If such an event is detected, the alert will trigger, and the action you specified will be executed. You can manage and review these alerts in the Alerts section under Security in Elastic, ensuring you stay on top of potential security incidents.