The simplistic Remote Administration Tool they call Sub7. When Mobman sat at home creating it did he realise the affect it would have, maybe not.

Trojans can give the backdoor advantage to any hacker, after cracking a server the last thing you want to do is to repeat the process, hence the backdoor created when you put that little trojan in there. Many a young man got into hacking through trojans, who are now purely ethical and laugh at the days of script kiddie fun.

It is just an over-used tool, create your own and your not a script kiddie. Simple?