Understanding the Issue:

The custom event handler for detecting SMTP reconnaissance activities is generating a large number of events.

This high volume of events is overwhelming the notification system, leading to potential alert fatigue and inefficiency in incident response.

Event Handler Configuration:

Event handlers are configured to trigger alerts based on specific criteria.

The frequency and volume of these alerts can be controlled by adjusting the trigger conditions.

Possible Solutions:

A. Increase the trigger count so that it identifies and reduces the count triggered by a particular group:

By increasing the trigger count, you ensure that the event handler only generates alerts after a higher threshold of activity is detected.

This reduces the number of events generated and helps prevent overwhelming the notification system.

Selected as it effectively manages the volume of generated events.

B. Disable the custom event handler because it is not working as expected:

Disabling the event handler is not a practical solution as it would completely stop monitoring for SMTP reconnaissance activities.

Not selected as it does not address the issue of fine-tuning the event generation.

C. Decrease the time range that the custom event handler covers during the attack:

Reducing the time range might help in some cases, but it could also lead to missing important activities if the attack spans a longer period.

Not selected as it could lead to underreporting of significant events.

D. Increase the log field value so that it looks for more unique field values when it creates the event:

Adjusting the log field value might refine the event criteria, but it does not directly control the volume of alerts.

Not selected as it is not the most effective way to manage event volume.

Implementation Steps:

Step 1: Access the event handler configuration in FortiAnalyzer.

Step 2: Locate the trigger count setting within the custom event handler for SMTP reconnaissance.

Step 3: Increase the trigger count to a higher value that balances alert sensitivity and volume.

Step 4: Save the configuration and monitor the event generation to ensure it aligns with expected levels.

Conclusion:

By increasing the trigger count, you can effectively reduce the number of events generated by the custom event handler, preventing the notification system from being overwhelmed.

Fortinet Documentation on Event Handlers and Configuration FortiAnalyzer Administration Guide

Best Practices for Event Management Fortinet Knowledge Base

By increasing the trigger count in the custom event handler, you can manage the volume of generated events and prevent the notification system from being overwhelmed.