Kaspersky has revealed there is a new virus going around called TDL-4. This one is special, in that it is designed to hide in peoples computers without their knowing, and is extremely hard to remove. Infections occur when visiting rogue web sites (usually pornography or pirated content). Be very cautious when visiting a website that you have not gone to before!
See the full article at cnet: http://news.cnet.com/8301-13506_3-20075725-17/tdl-4-the-indestructible-botnet/