WSO is a PHP shell backdoor that provide an interface for various remote operations. It can perform everything from remote code execution, bruteforcing of servers, provide server information, and more.

Download (packetstorm) Link :

Features:
Authorization for the cookies
Server Information
File manager (copy, rename, move, delete, chmod, touch, create files and folders)
View, hexview, editing, downloading, uploading files
Working with zip archives (packing, unpacking) + compression tar.gz
Console
SQL Manager (MySql, PostgreSql)
Execute PHP code
Working with Strings + hash search online databases
Bindport and back-Connect (Perl)
Bruteforce FTP, MySQL, PgSQL
Search files, search text in files
Support for * nix-like and Windows systems
Antipoiskovik (check User-Agent, if a search engine then returns 404 error)
You can use AJAX
Small size. Packaged version is 22.8 Kb
The choice of encoding, which employs a shell.


Changelog (v2.5.1):
Remove comments from the first line .
Added option to dump certain columns of tables.
the size of large files are now well defined .
in the file properties field "Create time" changed to "Change time" (http://php.net/filectime).
Fixed a bug that caused not working mysql brute force if there was a port of the server .
Fixed a bug due to which one can not see the contents of a table called download in the database.

Youtube link :

Another nice collection here: http://laudanum.inguardians.com/