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                             A COMPUTER VIRUS
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  The PC is one computer which seems to be constantly threatened by virus 
programs. The Dragon is more or less immune, but the Atari and the Amiga 
get their share.
  
Lots of computer virus programs are written just for fun and simply put a 
message on your computer to let you know they are there. But all virus have 
rather sinister implications and can be rather frightening, as they can 
make you lose work and are difficult to manage. Understanding a little 
about them, however, could put you in control.
  
Firstly they are simply programs, the same in principle to any software you 
buy, but secondly, they are spread by sharing disks. So the less promiscuous 
you are with your disks, the safer you will be.
  
Most of the programs you run are quite visible, but in addition to that 
there are many files or programs which are running behind the scenes. For
example, the software which runs your mouse.
  
If there is a virus in your computer, it sits there quietly waiting for you 
to run a new program, or put in a new software disk, when it makes a copy of 
itself into that program or on to that disk. This copying is, in fact, 
infecting the file or disk.
  
When somebody else uses that file, or runs the program on that disk, then 
the virus is copied on to their memory and bcomes active there, ready to
do damage to their system. A never ending cycle of disaster!
  
To prevent virus getting into your computer you need anti-virus software. 
This will check your computer memory, hard disk and floppies and when it 
identifies a virus will, in most cases, remove that virus from your 
computer.
  
To prevent a virus doing any damage to your PC, there are a couple of steps 
you should take.
  
The first step has to be performed as soon as you get your anti-virus 
software and before a virus gets anywhere near your computer.
  
Get yourself a clean new disk and FORMAT it so that it can initialise or 
startup your computer. If you don't know how to do this go to the root
directory of your hard disk - eg  c:/> and type FORMAT /? and this should 
give you the options available if you are using MSDOS 5 or 6. On my PC I 
would put in a new high density disk into the A drive and type from the C 
prompt FORMAT A: /s/v.
  
Once the disk is formatted copy your anti-virus software to it and slide 
the tab so that it cannot be written to and so it becomes virus proof. This 
disk is now a SAFE DISK.
  
If you do get a virus you are now prepared.
  
You can start the virus using the SAFE DISK without activating the virus 
and use the anti-virus software to start cleaning up your hard disk. 
  
If you don't have a SAFE DISK, there's no guarantee that the virus won't 
keep re-infecting your hard disk while you are trying to clean it up.
  
The final step you have to take is to check and clean every floppy disk 
that you own. Yes, I do mean every disk. I will presume that you are NOT
using original software disks, but have always protected these and backed 
them up, before using the backups. If you haven't you'll have to check the 
originals too and there is the possibility that you may be taught an 
expensive lesson.
  
There are thousands of virus programs in existence, but only a handful of 
these are at all common and likely to come your way. On one never to be 
forgotten occasion I played host to THREE of them - TEQUILA, PARITY BOOT 
and MALTESE AMEBA.

The latter only infected one disk and was spotted when I scanned disks 
people sent me! The first two, however, meant I had to check every disk I
possessed and the first masked the second. The anti-virus software I had at 
the time (Nortons) only detected the Tequila and it was not until someone 
sent me a SAFE DISK containing McAfee's anti-virus program that the PARITY 
BOOT virus was revealed. I had to check all my disks AGAIN! This virus meant 
I needed professional help and Jason Shouler cleaned my hard disk for me.

The maxim is - good anti-virus software (and I can recommend McAfee's which 
I see advertised at #29.00 plus VAT - but at PC WORLD is #29.99 inc VAT) and 
a properly prepared SAFE DISK will protect you from the majority of virus 
out there.
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This article is a mangled version of the talk on Virus problems that 
appeared in the BIG BYTE, the ITV computer program.