An Auto Scaling group fronts EC2 instances behind an ALB and the application is receiving malicious traffic originating from a single public IP. You must block that IP address from reaching the application. Which solution will block the IP effectively?

AWS WAF (Web Application Firewall) is designed to protect web applications from common web exploits and bots. By creating an IP set with the malicious IP address and a web ACL with a BLOCK rule, AWS WAF can effectively prevent traffic from that specific IP from reaching the ALB and, consequently, the application. Adding a security group rule to the ALB is incorrect because security groups are stateful and primarily allow traffic; they do not have explicit deny rules for specific IPs in the same way WAF does. Amazon Detective is a security service for investigating potential threats, not for actively blocking traffic. AWS Resource Access Manager (RAM) is used for sharing AWS resources between accounts, not for traffic filtering.