Anyone know how to creat 1?

 

Easy... you do not ask here. It's illegal.

Find somewhere underground.

 

Go on Amazon and order lots of books in some of the languages you want to write one in and learn it. C++, Perl, Javascript etc. In theory if you want to know how to break something then you ideally know how to make it.



Not if you make a joke one which causes no harm, more prank based and isn't released into the wild.