First, my details :- Windows version : XP-pro SP2 (patched, confirmed with Secunia site inspector) AVG version and virus db version : 7.5.487 and 269.13.21/1010 Other antivirus software installed : nil Other protection software installed : AVG anti-spyware 7.5, ZoneAlarm free 6.5.737.000, ProcessGuard free 3.405 I had bought a Western Digital external harddisc in Feb 2007, and it came with their software WDSync. I don't use the software; instead I backup my data files to this external HD using Explorer copy function. However, before starting to use the external HD, I had copied (not installed) the WDSync.exe file to my internal harddisc as a precaution. At that time, AVG did not find any issue with this WDSync file. Today, I did an online scan from TrendMicro website, and TrendMicro informed that the only malware in my PC is a generic low-threat trojan, viz., avg75free_432a861.exe (which I had downloaded on 31st december 2006, before installing) ! Although TrendMicro wanted to clean it, I did not allow. I have kept a screenshot of TrendMicro's results page. However, while TrendMicro was scanning, AVG suddenly popped up and gave the "trojan SHeur.NFD infected file (WDSync)" message. Interestingly, TrendMicro didn't find this file to be infected. I have not yet been able to submit the file to jotti, since their server is continuously busy. However, I tried to upload at NormanSandbox and their server returned error (file could not be uploaded) ... this makes me even more suspicious. At present, I have moved the file to vault. Thanks.