Even if you change your pw and such. Did you fix your email? If they hacked your wow accounts I'm sure they hacked your email also.

Always change your email when your account has been hacked.
If you did that then I would suggest a cleaning of the computer. Better safe then sorry now.
I had a friend who has been hacked 6 times since wow was released. He finally changed his email information and has not had a problem since. He even cleaned his hardware system after each hack and that did not stop them. This last time they revived his account with a game card and blizzard wasn't going to do anything about it since the dude paid to reactivate.
Now that he changed his email with a clean system he hasn't had another problem.

Also adaware/spybot etc only truely work if you buy the programs and don't use the free service.