Fucktards are a kind of unstoppable elemental force. You can't rely on their sense of decency, you have to keep on top of the situation. So yeah, it can be your fault if you like.
Radix is right (if you doubted it), that fix has been out for a while. People rarely update stuff, though, that much is understandable.
AT: Hackers and crackers are blurred definitions. They're both to do with getting past security measures (in the computer context, crackers originated from disabling copy protection or exploring computer code generally) but there are professional hackers which have permission to find vulnerabilities.
I have backups of both the site and databases but i'll only fully remove and restore as a last resort as there very well may be an easier way to sorting the problem.
Re cracking/hacking:
Hacking just means spending ages hacking away at your keyboard trying to get something to work. You can hack out a story, or a program, or a school assignment, or whatever. It's a pretty generic term that comes from the guys who ran the "rat's nest," a huge tangle of cables that ran a complicated model train display somewhere. Apparently they used to spend ages hacking away at the cables trying to get something to work.
Cracking means figuring out someone else's work when they don't want to. It comes from "cracking a code." You can crack someone else's program to get it to do something different, or crack the security on a remote system. It's generally bad. All crackers are hackers, but few hackers are crackers.