Downloader-UA filling up Drive with Porn

I have been removing Malware from a friends computer and found that it had (or still has) a Trojan called Downloader-UA by McAfee. The Trojan has created a hidden folder: C:\documents and settings\[username]\!. That’s right”!”. The hidden folder contains Porn in the form of .avi files. I know that it’s Porn by the filenames. I’ve tried all the “show hidden files” settings in Windows but still can’t see or get into the folder. I let the antivirus software run for several days and Quarantined about 20,000 of these, and deleted them manually by going into the Quarantine folder. McAfee didn’t have the capacity to load them for view. When I finally was able to look at a small sample of them in Quarantine the antivirus software listed all the .avi files under the Trojan name Downloader-UA, and the path was the “!” folder. I had to give up since the owner wanted the computer back for the weekend. There could be tens of thousands more .avi files on the drive and the drive is larger than 100 gig. I think it’s the Parental Guard part of McAfee that is removing them because Symantec just scans them and doesn’t delete them. When I check folder sizes and drive sizes everything looks normal, so Windows must not be detecting the drive size or folder size correctly. My problem is that I can’t get into that folder to delete them manually. I’m not sure why the Trojan is downloading these files onto someone’s hard drive. For use later? Anyway, I thought of trying to get into the “!” Folder using DOS and will try this Monday. This is an XP box. Does anyone have any suggestions? This is really puzzling me, and I’ve been working in IT for 20 years. I know there is software out there that can “Hide, lock and password protect private files and folders from other users”. Sorry that this post is so long, I just wanted to make it clear what’s going on.