What I would do is make sure your anti-virus is updated, disconnect your computer from the internet(maybe excessive, but I do it because I feel better), run a full system scan. You may have to do it from safe mode to remove whatever got in(if it anything really did get in). I'd suggest after making sure everything is clean you change all of your passwords. Excessive? Maybe, but what are your accounts worth to you?
I also don't know what type of firewall you use, but I use Kerio Personal Firewall. It'* a free firewall that gives you 30 days to try the full version. After that it cuts down to basically blocking applications that try to run without your permission, unauthorized IP addresses attempting to access your computer, etc. I feel it'* an excellent program from my little experience. In advanced mode, if something tries to run, and you haven't previously authorized it, it asks you before it lets anything happen. I mention this because I had a similar situation happen, but Kerio caught this new program/worm/trojan/whateverthehellitwas trying to get access to a remote point and asked me what to do.... DENY!
With all of the above mentioned, I would like to say that I seriously hope I am wrong. I hope I just over-react to this sort of thing. Best of luck and I hope no further damage has been done.