I ran a virus scan on my PC today and it came up reporting two infected files. Both of them were files that contained purchases I had downloaded from Renderosity. The virus scanner reported that they had hidden extensions: they appeared to be .zip files but were in fact .zip.exe. One of them I had already opened with no apparent ill-effects, and it may be this is a needless scare. For this reason, I do not post here the names of the files or products, as I don't want possibly to prejudice the vendors involved, who I have no doubt are totally innocent. Nevertheless, it might be an idea to look into why these hidden extensions have been found.