Possible Account Hack...I need some Advice Please

Ok so I get home last night and went to log on and was informed I had gotten a 3hour suspension due to something along the lines of Spamming Chat and trying to Sell Gold for real World Money. Now my next door neighbor said she saw me logged on at about noon time...while I was at work. I have just recently added some add-ons to my game, not sure if that is the cause or not. Maybe if some of you know of add-ons that are trouble you could let me know. My neighbor also told me I should get an authenticator, which I will be getting as soon as I have the money. Thank you all in advance for any help or advice you may be able to give me.

"Why don't you have an authenticator in the first place" is not helpful and is just being a jerk.

Spazz,

*CHANGE YOUR PASSWORD. Right now. Maybe on somebody else's computer--yours may have a keylogger on it.
*Buy an authenticator. If you have an iPhone or iPod touch, there is a FREE app that will act as an authenticator as well.
*Check your computer for viruses. Check any computer that you have logged into WoW with recently for viruses.
*Check if any of your stuff or gold is missing.
*Don't give your new password to anyone, even a friend. If you have to share your account for some temporary reason (like one of my guildies who sometimes loans her alts on her 'extra' account to guildies to fill out a raid or a heroic) you should change your password to something temporary when you need to share, and then immediately back to a 'secure' and 'personal' password.
*Check the internets to find out if anyone else has reported problem with the *specific addons* you recently installed AND/OR the *addon installer* (Curse client, etc). Sometimes these addon updaters can end up giving people keyloggers and such. If you downloaded, for example, Power Auras, you might google "Power auras keylogger" and see if a rash of recent complaints come up. Usually if there's a correlation a lot of other people will be having the same problems and asking the same questions.