Virus?

I`ve been pulling my hair out for days trying to figure this one out.

A couple of days ago we got in a PC that wouldn`t boot. Reported the IDE drive as an invald system disk. Checked/replaced system files - same problem. Ran both Norton and Mcafee boot scans - nothing. Fdisk /mbr. Still there. No important data so low-level format and reload. Solved the problem.

But now we have three other PCs with similar symptoms. (someone had been using bootable floppies with the write protect off....) But two of them have McAfee installed and when it tries to run ScanPM I get a DOS screen with what looks like hexadecimal addresses all over it and the machine hangs.

I`ve downloaded the latest updates to Norton and McAfee but they still find nothing. I could just format again, but I want to find out what is causing this in case it spreads.

All ideas will be gratefully received.

You are right on the money about the floppies. I think you are dealing with an old virus that is starting to show up again(at least in our area) It is only transfered via floppies. I think it originated about 1995. For a full description search for NYB which is the original name, sometimes called Stone. It is very stealthy and is a mbr virus and relocates the original MBR. what make this tough is any time you boot the virus instantly goes to the top of the system mem just below the 640k boundry. Anyway check out NYB or Stone. Hope this helps

I came into this same type of problem. I finally fixed it with a AVG boot disk(www.grisoft.com).

Cheers for the help guys, I`ll check up on the Stone virus and let you know what happens.