[MidgetMage55]

The thing about addons is they don't even execute until after you have entered your password/account name. Specifically when you select your character and start to enter the world is when they begin to do what ever it is they are designed to do.

So unless your addon required you to use an executable file to install it (an extremely rare creature these days as far as addons go) you are basically in the clear.

This by no means is saying you shouldn't practice safe internet habits. as mentioned above you should scan your files to make sure they are safe. Keep your scanning software up to date. Also do not rely on security software obtained from torrent sites (not to imply you are doing so. just being thorough) as they are difficult to keep up to date in a timely fashion. This is assuming they are clean to begin with.

Another overlooked but relevant issue is using the same login name and password for most if not all web related activity. All it takes is one of the locations to be compromised to put all the services you use at risk. A rule i follow is if its important enough to protect then a unique login and password are worth the trouble. This goes the same for sharing info with someone. Unless you can be absolutely sure they wont do something stupid with your info. Don't give it out.