I have a customer experiencing severe slowdowns on their PC ... caused by NOD32! At least, that's the way it seems. When affected, CPU utilization of one of the NOD processes (nod32krn ?) goes to 100% while some files in the Eset\updfiles folder grow to as much as 30-40GB each! Interestingly, the file names are normally nodxxxx.ver, whereas other PCs only have upd.ver and lastupd.ver. There's also a bunch of nodxxxx.nup files; some (eg nod653D.nup) are only 28kB but others (eg nod249E.nup) are a whopping 4GB. They have a second, little used PC which has not been networked except for a brief time some months ago (to transfer some files to the first PC). Yesterday, I discovered it had the same problem (on a smaller scale), suggesting the infection/problem may have originated from this older PC. On the first PC, I had already reinstalled NOD32, run HijackThis, Ad-Aware etc. I also installed TrendMicro's Housecall, which found one or two gremlins that NOD32 didn't (and vice versa). Yesterday, I tried Process Explorer but couldn't spot anything untoward. If this is malware, it's a) incredibly rare and b) extremely sophisticated. Incidentally, it doesn't look like the files are being downloaded from the Internet - usage is normal, and the second PC was only ever on dialup. Any ideas, or preferably solutions from Eset, much appreciated.