I just launched a new browser session, went to flyertalk, and had the window close and a bogus dialogue start about needing to download "anti-spyware master" with some fake screens (obvious since they were faking windows but I am on a mac) - it then downloaded a .exe file (fortunately this is a powerpc mac so windows .exe's don't run).

Clearly the result of a rogue banner ad on FT - I suggest you check into it and complain to your ad serving companies.