I got the same alert about VBS-Zulu (Virus/Worm) when I first went to the web site and on 2 refreshes. After that no more warnings. Its seems to be related to the link at the bottom left corner about validating with Windows Genuine advantage.
I tested this with avast! home on Avant Browser (an IE shell).
EDIT: I just noticed the link changes with every refresh so the one I mentioned above is not the offender. Its the three that were not displayed that caused the alert.