Copyright ©1996, RF Specialties Group.
Viruses
are destructive programs that attach themselves to executable files, and are passed
from computer to computer on floppy disk or by modem. Your computer becomes infected
by the virus when you run an infected file. It then propagates itself onto other
executable files in your computer as you run them. It may tamper with your hard
disk or with your memory, and may destroy files on your hard drive. With our modern
connectable world, computer viruses are becoming an increasingly common problem.
If you don’t take steps to practice "safe computing", you stand the risk of eventually
losing some or all of your hard disk data to a virus. Here are some easy steps
you can take to protect yourself.
1. Get a good virus check program, and periodically scan the files on your hard drive. Be sure you have a current version of this program. There are thousands of viruses in circulation, and hundreds of new ones are created each year. Your two year old virus scan program will not protect you against the newest strains. One of the most comprehensive programs on the market is offered by McAfee, and is continually updated to include the latest viruses. It can be downloaded from CompuServe (GO MCAFEE), or you can call them at (408) 988-3832.
2. Your scan program will not reliably detect a virus if the computer’s DOS is already infected. Make a boot disk which has a known "clean" copy of DOS, copy the scan programs onto that same disk, and close the write protect tab. Whenever you want to scan your hard drive, boot your computer from this floppy disk and run the scan program from the disk.
3. Be suspicious of any executable programs (*.EXE, *.COM, etc.) or macros that you receive on floppy disk or via modem. Use your scan disk to check them before running them. The latest angle is said to be a *.ZIP program that does its damage when you try to unzip the file. NEVER unzip or run any files you receive via e-mail unless you know the sender.
4. A virus can hide in one or more of the following locations: attached to an executable file, in your computer’s memory, or in the boot sector of your hard drive. If a virus attaches to an executable file, the size of that file will increase, so this is an easy way to spot a virus. Print a directory of your executable files so you have a record of the correct size of each file. If you later suspect a virus, check this list against your current file sizes to see if they still agree. The most common file a virus will attach to is COMMAND.COM. Here are the correct file sizes for some versions of COMMAND.COM as originally released by Microsoft:
5. Put a write protect tab on all your master software diskettes. If your master copies become infected, you could lose your investment in the software. Consider write protect tabs to be "condoms" for your disks, and use them liberally.