Several readers pointed out that the site was hit by a virus yesterday.
We tracked it down to a Trojan from our ad service – Wikiinvest. (Reader comments suggest that it was the js:Downloader-BAA [Trj] trojan, which came from the roboqfox.dyndns.tv website).
We’ve terminated Wikiinvest effective immediately, and have had no further virus problems.
Sorry for any inconvenience.