HULK stands for HTTP-Unbearable-Load-King. It’s an HTTP denial-of-service tool that has been around for several years. This tool, written in Python, is able to generate unique HTTP requests that are designed to stress test web servers against resource exhaustion. HULK generates unique requests based on the user agent/referrer strings. By requesting the HTTP server for no cache, the server presents a unique page for each request. The tool bypasses caching engines and hits the server directly. Since its release, several actors have optimized and republished this code to include more user agents and referrers in an attempt to generate more randomized requests while launching an attack.