Q u o t e: yep, make sure you're actually on the appropriate website before entering your password, don't execute suspicious files, and don't let anyone with physical access to your computer install a keylogger on it. if you follow these three rules, you are doing everything possible to prevent your passwords from being stolen.
there's nothing to be done about your stolen war3 account though
+ that you're paying very little for this lesson. It could've been your bank account or your credit card info that was stolen. So be careful in the future.