Reducing False Positives from Specific Lambda Functions

Repeated false positives originating from specific AWS Lambda functions can generate noise and distract your SOC team from genuine security events. Sweet Security offers several features and best practices to help you tune alerts for your unique environment.

Step-by-Step: Tuning Alerts for a Lambda Function

1. Review Alert Details

Examine the alert payload in the Sweet Security dashboard.
Confirm the function name, AWS region, and triggering rule.
Check related CloudTrail or CloudWatch logs for context.

2. Identify the Root Cause

Common triggers:
- Use of temporary or assumed credentials by automated jobs.
- Scheduled Lambda invocations that resemble threat patterns.
- Non-standard policies or excessive permissions.

3. Mark Known Good Activity

In the dashboard, flag specific Lambda events as “known good” if they represent expected behavior.
Add the Lambda function to an allowlist or suppression policy (if available).
Document business justification for monitoring/auditors.

4. Update Detection Rules

Adjust sensitivity or refine the rule scope for this function:
- Scope alerts to specific IAM actions.
- Exclude internal service accounts or deployment tools.
- Limit triggers to uncommon or suspicious operation patterns.
Save changes and test with non-production workloads.

5. Monitor and Adjust

After tuning, monitor alert activity for several days.
If necessary, revert or further refine changes to balance detection with noise reduction.

6. Contact Support (if needed)

Open a ticket via the support portal with:
- Function ARN and region
- Recent sample alerts (JSON preferred)
- What tuning steps you’ve tried
- Your expected/desired outcome

Tip: Including logs and timestamps helps our team accelerate diagnostics and remediation.