You can also look up for these other topics:
Framework
Coding Standards
Boilerplate
CMS
Tool
Security
Hacktoberfest
A collection of PHP backdoors. For educational or testing purposes only.
bartblaze🎯 PHP / ASP - Shell Backdoor List 🎯
backdoorhubA PHP Based Tool That Helps You To Manage All Your Backdoored Websites Efficiently.
Tuhinshubhra