Adaware is excellent. It is what I use and highly recommend it.
However, the possible Trojan nature of the particular problem might indicate looking at the link I posted before.
But, maybe not as I have not removed this one myself. However, since apparently virus scanners are recognizing this one...
Also, a good online virus scanner is
http://www.antivirus.com. It is free and very good.
-JmE-