Hacked..how?

I fully understand but it doesn't make sense at all. Please clarify

however, a hacker (programmer) writer, etc, may have special permissions to run bruteforce programs on systems lifted off of the original program

Meaning someone is separating the information from the actual website itself and running a program off of the information instead of the server.

How would this happen? Please go into detail as I am genuinely interested.

 

Yes always put a pin on the account. Currently people have made bots to guess but after a certain amount of tries they cant keep guessing. Pin is the way to go.

 

I'm only going to comment on the virus scan bit.

Software to scan for viruses, malware etc are basing it on definitions in their database. New definitions are added very regularly as they are discovered, but that means that until they are added...it won't detect it.