Can any virus survive reformatting the hard drive?
by baggypants - 12/8/04 12:44 AM
I have heard from a couple of sources that some viruses or perhaps worms or Trojans can remain intact on a hard drive even after it has been reformatted. I recently inherited a computer running Windows 2000 that was badly infected with over 1000 viruses. Norton AntiVirus was able to clean, repair or quarantine all of the viruses, software was reinstalled, the computer seems to be working normally, and no viruses are now found on a comprehensive full system scan.
I was warned by a local computer technician that even though the computer scans clean and is working well, that I shouldn't put it back on our local network because there is a small region on the hard drive that is not overwritten by normal formatting and some viruses are known to hide there. He suggested that it was still possible for this computer to infect other computers on our network.
That seems difficult for me to believe. All of our computers are running virus scanners. It would seem to me that, at least if it were a known virus, it would be recognized and stopped immediately if it reappeared and tried to spread to another computer.
Has such a threat ever been documented? Is there any reason to fear that this computer could be harboring a significant threat to other computers on the network? If there were a virus or other threat that is so invisible and difficult to remove, wouldn't it be just as reasonable to think that it could be present on any computer with similar protection?
Any insight offered is greatly appreciated.