Yes, for IE only. When I use firefox, everything is fine.
Oh, the virus warning also pop up when I try to start an online game called "Audition". The game browser will load a notice page from its website (
http://audition.nexon.net/Game/notice.html) before I can log in to the game. So I assume that the game browser uses IE to load the page. I'm not sure about this though. Anyway, I'll try System Repair Engineer that you suggested.