Get the Whitepaper called Paraisiting web server process with webshells in permissive environments.
You can download it from the following link: https://packetstormsecurity.com/files/download/146608/parasiting-web-server-process-with-webshells-in-permissive-environments.pdf
Source: https://packetstormsecurity.com/files/146608/Parasiting-Web-Server-Process-With-Webshells-In-Permissive-Environments.html