Final answer:
The suspicious traffic on the web server appears to be a Cross-Site Scripting (XSS) attack.
Step-by-step explanation:
The suspicious traffic on the web server is displayed in the given WAF logs. From the image, we can see that the request is trying to inject code in the URL's query parameter by appending a script. This is indicative of a Cross-Site Scripting (XSS) attack.
XSS attacks occur when an attacker injects malicious code into a trusted website, which then gets executed by unsuspecting users, compromising their data or stealing sensitive information. It is important for the security analyst to investigate further and apply appropriate countermeasures to protect the web server.