Virus hiding on Master Boot Record?

Question

Hi!
1. I read on many forums that there are viruses that can hide on MBR and survive from the format. The only thing to do is create a Win98 startup disk and use the fdisk utility. Is this correct?
2. And also, I am afraid that the virus will spread to my flash disk and memory stick. Is a mbr exist on those media? If yes, can I use the FDISK to resolve the problem as well? So long, I scanned them using NAV on my campus and no virus found.

OK. Thank's to all of you for your answer! To clear my doubt, if I scan my flasdisk and memory stick, if the norton anti virus found that there is no virus is it mean that my computer is now 100% save? (after I scanned the flashdik I will not connect it to this computer anymore until I have completely format (fdisk/mbr)). Thank's again!!

Answer 1

1. Yes, a virus can infect the MBR of a hard disk. Yes, it will survive a high-level format - because such a format clears only the FAT and the DOS Boot Sector. It won't survive a low-level format - but you probably won't be able to do that on your hard disk anyway. Booting from a known virus-free disk and using FDISK/MBR is indeed a convenient way of removing most viruses of this kind. However, it is not a fool-proof way. Some MBR infectors can survive that, using various tricks. It is much better to use an anti-virus program that knows how to remove the virus properly. It is very unlikely that you have such a virus, though. They became essentially extinct with the advent of 32-bit operating systems like most modern brands of Windows - because once the OS is loaded, such a virus can no longer function. Such viruses were extremely widespread during the time of MS-DOS, though.

2. Flash disks don't have MBRs. They do have a DBS (DOS Boot Sector) which can, theoretically, become infected. In practice, though, this is extremely unlikely. After Windows loads, a boot sector virus would be disabled - and before Windows loads, the Flash disk would be inaccessible, because the drivers for accessing it are not loaded yet. Besides, even if the DBS of a flash disk becomes infected, the virus won't be able to spread any further, because you don't boot from flash disks. But, no, FDISK cannot be used on removable disks - only on hard disks.

To summarize, you most probably don't have a virus of this kind, so don't worry about it.

Answer 2

Yes an MBR can become corrupted.
Best way to fix it initially is by running a Full scan from a Boot CD.
Start up Press F12, then Run the AV from the CD and Repair that way.
Alternatively. start a repair from the install disk and either do a fix mbr or A replace MBR.
Virii can spread to Flash disk and similar. The File table is not the same as the HD mbr, but it can be scanned and repaired easily with an antivirus scan

Answer 3

Any virus program worth its salt that you purchase over the counter should have a boot disk. This is a floppy that you insert in your drive and then start up the PC. Its only purpose is to make certain that you do not have a virus on your MBR and is really the only way to make sure that you don't.

A couple of afterthoughts; the floppy must be compatible with your OS, the disk must be write protected when you use it. If you are going to get rid of your OS and start over then all you need to do is delete the partition (if you have the capabilities of writing 0's to the HD do this, some partitioning programs allow you do do this) and then reinstall your OS.

Good luck, a virus in your MBR is really bad news.

Answer 4

MBR viruses are EXTREMELY rare. They were popular in the early-to-mid 90's, but they've all but died out by now. If you think you have one, you can use FDISK. Type "fdisk /mbr" and it will reset it to the default MBR, so you won't need to reformat or anything. It'll just clear the MBR.

Answer 5

1 if you are using windows XP then you cant get a virus in the boot sector
2 if you are still using windows 98 you might want to think about upgrading because windows Vista (the 4th operating system after 98) will be coming out somtime this year
3 flash drives do not have a MBR

Answer 6

u must format the hd, use win98 start up and go to fdisk then you have to delete the ms dos partition. then create a primary dos partition. Then re-start the PC with the disk 1 and then put win 95 in program and up-grade to win 98

Answer 7

Use Kasperskey Anti Virus, it will detect the most viruses if you update the program over the internet. Checkmark the option to scan the boot sector.

Answer 8

Yes...a reformat of the hard drive will get rid of the virus...and no there is no mbr in flash drive.

Answer 9

convinced, you're greatest. i'd deploy all updates to abode windows 7 that you locate appropriate first. service Packs will favor to be downloaded and put in earlier you flow some thing over, imho. playstation use sixty 4 bit deploy. 32 bit is shaky! good success.

Answer 10

Try http://grisoft.com

I use their Anti-Virus/Firewall combination. It's cheaper than Norton and is Extremely Sensitive.