What do you wana learn ?
Cracking or Hacking ?
Cracking is easy,
Use Sub-7 trojan to get access on to kissi key bee system per. But you need to send a client file 1st.
And then you can control his/her computer from your computer.
Back Door....is a pro tool.
Have used it.
There are many tools...
But be a good cracker and learn it by programming. Where you dont need any wares.
Thats what CRACKING is