I saw a thread on this in the 360 forum, which I found simply by searching "PUP.Optional.OpenCandy" on Google. For some reason searching on the same text string within the forums comes up empty, as does a search for only "OpenCandy" or "Open Candy".
However, as I typed in the subject line of this message, it popped up in the list of suggestions. Go figure!
Since the original poster had no idea of the source of his infection, I thought I would provide some information here. MBAM also detected OpenCandy on my system just now. In addition to the installed files and reg entries, I still had the original downloads in my Download folder, so I can identify at least two potential sources.
In addition to the infection, OpenCandy was found in FreeYouTubeDownload.exe and in FreeAudioConverter.exe
As they say, you get what you pay for, and these downloads were worth just what I paid for them, after deducting the aggravation of a malware cleanup from the convenience of using the host product.
At least I can keep using the host product after I get rid its nasty little companions. Apparently, they are not embedded in the FYTD nor FAC apps themselves, but are intalled without the user's permission by the same setup file.