To asnwer your question: It means it found the trojan. Trojans dont contain virus'. If you have a trojan client installed in your sytem someone with the server can access your ****. It's that simple. It really has nothing to do with a virus at all.

Anti-Virus software oftem lack definations for trojans. Get something like The Cleaner which isnt an AV at all...it's specifically for trojan detection.