I know that when somebody writes code to create a virus, they have to choose a programming language. Do they choose this programming language based on the fact that it writes more powerful virus's or that it gives the virus an advantage in someway for the computer network it is attacking.

EXTREME NEWBIE QUESTION: When somebody hacks into your computer network system, they are using Unix and programs they written or shared to break in, steal documents (or erase data or something) and than cover their tracks, right?