WAF Detection of Malicious HTML & PHP

TL;DR

Yes, a Web Application Firewall (WAF) can block or detect crafted HTML files and obfuscated PHP scripts/shells. The effectiveness depends on the WAF’s ruleset, configuration, and the sophistication of the attack. This guide explains how to improve detection.

Detecting Malicious HTML

1. Understand Common Attacks: Crafted HTML often uses techniques like:
   • Cross-Site Scripting (XSS): Injecting malicious JavaScript into trusted websites.
   • HTML Injection: Altering the website’s structure or content.
   • Phishing: Creating fake login forms to steal credentials.
2. WAF Rules for HTML: Configure your WAF with rules that look for:
   • Suspicious Tags: