This comes from Heise online…never heard of it, and so I checked WOT, and it’s ok.
http://www.h-online.com/security/services/browsercheck/
The one I was most concerned about was at:
http://www.h-online.com/security/services/browsercheck/demos/moz/mozdemo1.shtml
Which is reading files via HTML. Avira picked up the file as suspicious through the heuristic, and so I clicked ignore. But I realized that Vista has least privileges by default, and so the root of the drive can’t be accessed anyway.