AWS WAF logs contain detailed request-level information, including source IP addresses, requested URIs, and rule matches. According to AWS Certified Security – Specialty guidance, enabling AWS WAF logging provides the most reliable and tamper-resistant method to investigate web-based attacks, especially when instance-level logs are unavailable.

By streaming WAF logs through Amazon Kinesis Data Firehose to Amazon S3, the company ensures durable, centralized log storage that is independent of EC2 lifecycle events. Amazon Athena can then query the logs efficiently to identify repeated requests to the new-user-creation.php endpoint and extract attacker IP addresses.

VPC Flow Logs do not capture HTTP-level details. ALB access logs alone may not capture blocked requests. WAF logs provide the best forensic visibility for future detection.

Referenced AWS Specialty Documents:

AWS Certified Security – Specialty Official Study Guide

AWS WAF Logging and Monitoring

Amazon Athena Log Analysis