As long as you have a connection via the Internet, you can get it all down, at worst, therefore I propose real-time protection, update at least once per hour, which is necessary and if it has web scanning (remove viruses from web traffic), it is a plus,here is links for "bad thing"
http://www.bleepingcomputer.com/viru...ing-tdsskiller
http://www.f-secure.com/weblog/archives/00001976.html