
What is Shell ?
A shell script is a script written for the shell, or command line interpreter, of an operating system. It is often considered a simple domain-specific programming language. Typical operations performed by shell scripts include file manipulation, program execution, and printing text.
This is a plain c99 shell, BUT it is Undetected so you should not get a warning from a anti virus if you download it. (update: not Undetected anymore )
I am not going to explain SQLi just how to deface.
Sql Tut- http://hackingmania.com/Blog/sql-injection-and-defacement-for-beginners-tutorial
So now go get yourself a vulnerable site, hack it and get...