SyRiAn Sh3ll is a PHP backdoor that allows for database access, local exploitation of the host, and more.
You can download it from the following link: https://packetstormsecurity.com/files/download/102849/syrian-shell.tgz
Source: https://packetstormsecurity.com/files/102849/SyRiAn-Sh3ll-7.html