Contents of the MDISK.DOC file
MDISK - Boot Virus Remover
from McAfee Associates
* * * * W A R N I N G * * *
Do not attempt to use these programs until you have
contacted McAfee Associates at 408 988 3832. These
programs can cause damage to your disks, and instructions
for the use of these programs use may vary depending on the
type of virus that you have contracted.
MDISK Programs are utilities designed to remove generic boot
sector or partition table viruses such as the Pakistani Brain, Den
Zuk, Bouncing Dot, Stoned, Alameda or any other boot/partition
virus. It will remove these viruses from any bootable disk,
including floppies, and will return the system to an uninfected
state. Note that you must use the appropriate MDISK program for
the version of DOS that your system was originally formatted under.
The MDISK programs are:
MD40.EXE for MS/PC DOS 4.0
MD33.EXEfor MS/PC DOS 3.3
MD32.EXEfor MS/PC DOS 3.2
MD30.EXEfor MS/PC DOS 3.0/3.1
MDISK provides three options:
MDxx FThis option is used for disinfecting floppies.
It will disinfect the diskette placed in the
boot floppy drive (first configured drive in
MDxx PThis option will cause only the partition table
of the bootable hard disk (first configured
hard drive) to be disinfected. The fixed disk
DOS boot sector will be ignored,
MDxx(Default) This option will cause the partition
table and the DOS boot sector of the bootable
hard disk to be disinfected.
To disinfect an infected system, first power down the machine
and then boot from a clean, write protected floppy. Then type the
appropriate MDISK command. If you are disinfecting a hard disk,
power down the system again immediately after running MDISK, and
then re-boot from the hard disk. This will circumvent the
possibility of the virus surviving in system memory.
MDISK should only be used on systems in which a boot or
partition infection has been confirmed. To confirm an infection,
run the VIRUSCAN program to determine the type of virus. VIRUSCAN
may be obtained from the McAfee Associate's BBS - 408 988 4004.
Using MDISK will incur a slight chance of boot sector damage (less
than 2%) on systems that are infected or uninfected, and the result
could be a hard disk that is no longer bootable. If this occurs,
the DOS SYS command must be used to restore the bootable status
(see the DOS Users Manual). MDISK may also leave remnants of
virus code in unaccessible sectors. These remnants are harmless
and will no longer be accessible after MDISK is run. However, some
small amount of space (usually less than 3K) may be wasted on the
hard disk as a result of running MDISK.
The MDISK programs are shareware products produced by McAfee
Associates. They may be licensed for $25 by individual PC users.
Corporate site licenses are also available. Please send the
license fee to: McAfee Associates, 4423 Cheeney St, Santa Clara,
CA, 95054. 408 988 3832.