This has happened to me a couple of times while using Prevx. It'll pop up with a message like active malware detected or something -- I don't know what it says exactly because the message disappears rather quickly. This time it popped up with an actual file name -- it had driver something in the name -- before it vanished. Prevx then starts scanning again and returns a system clean message. Now, usually I'd go into the undo cleanup menu in prevx to see if it has quarantined anything, but it tells me that prevx has not cleaned anything and when I try to save a scan logfile it opens notepad and tells me "Access is denied." I've reinstalled a couple of times now and it has only identified the infection about three times now. Prevx tends to detect it shortly after install and subsequent scans detect nothing. I'm not sure what's going on and I'm a little paranoid.