Sounds serious if you are now a spambot. Needs fixing.
Here in the UK, we have a weekly, half hour BBC TV programme on PC and tech news.
They did an exclusive on this subject recently. See clip at
http://news.bbc.co.uk/1/hi/programme...ne/7932816.stm
Also, have a cruise round their website for general interest.
(if outside UK, maybe only the International video links work)
I use Avira from avira.com free anti-virus which I find very good.
(never run two AVs at same time, turn mcafee off if you want to try it)
Also see a lot of references to SpyBot/mbam/hijackthis/combofix.
I did try combofix in spite of dire warnings to only use it under supervision by a moderator. Created my own restore point first, but it makes another. Didnt do me any harm.
(download triggers a virus warning- APPL/PsExec.E. Allow it.)
Also check the malware forum on this site. Good luck.