Computer Viruses have hit the headlines quite often in recent months. Paul Overaa takes a look at the current risks and explains what can be done by the computerised musician to minimize the dangers.

Computer viruses have been in the news several times recently and although there's much interest in them there are still a lot of misconceptions about what they are, how they work, and how much damage they can actually cause.

What is a computer virus?

BASICally (sic - Ed) it's a computer program which is able to duplicate itself by either attaching itself to existing programs or by copying itself into free space on a computer disk. Every time the program, or the disk containing the virus, is used the virus program will load itself into the computer's memory and, unbeknown to the unsuspecting computer user, will continue to copy itself onto any new disk which is inserted into the computer. When these new 'infected' disks are used they then also continue to spread the virus program in just the same way that the original disk did! Floppy disks, hard disks, even programs transmitted using modems, can all carry and pass on virus programs and once these become active they continue to spread with similar characteristics to those of a real, i.e. biological, virus.

Computer viruses are not a new phenomena, they've been around for years but until fairly recently they have been restricted to large computer systems. A few years ago the average home and small business microcomputer was a simple machine, it had a small amount of memory and used low capacity disks — viruses were never seen simply because there wasn't enough space to write them and even if people had written such programs they would have been easy to spot. The computers which are in common use nowadays are more powerful and much more complex and this complexity has actually opened the doorway for the virus makers.

The new level of computer sophistication, coupled with increased memory and disk storage capacity has meant that computer viruses can now be easily hidden from computer users who may not be too familiar with the internal workings of their machines. The reason for the current concern is not then that these types of virus programs are anything new, it's just that they've now been given the opportunity to hit a mass audience. Unfortunately you, as a computerised musician, are a part of that audience!

As a serious computer user a modern day musician would probably say that they have quite enough problems to contend with, without worrying about viruses, but not worrying about them is not going to make the potential threat go away. Luckily you can, by following a few simple ground-rules, easily reduce your chances of accidentally picking up a virus program. Half the battle is to know a little bit about what they are, how they work and why certain types of computer user are more at risk than others - so the fifteen minutes you spend reading this article might prove to be fifteen minutes well spent.

Most viruses only ever become 'active' when you run a program or when you 'boot up', i.e. when you start up your computer system. Remember however that 'running a program' doesn't just mean running an applications program... system commands which copy and format disks, or those which list a directory, are computer programs just like any other - all of these system functions can be modified so that they help to distribute the virus.

A virus program, once present in a computer's memory, will usually stay there until the computer is physically turned off. It is not enough to just reset the computer - most virus programs will make changes to the actual operating system of the computer so that they will continue to work even after you've performed a reset command! Many such programs are harmless and were never written with the intention of causing damage but unfortunately some viruses exist which can and do interfere with a computers filing system and this can cause the unfortunate user to loose both programs and data. At the present time there have been relatively few cases of serious losses due to viruses and the biggest worry at the moment is just the potential threat that these types of programs pose. At the moment such risks are usually small but... they are real and virus attack is becoming increasingly common so it doesn't make sense to pretend that 'it could never happen to you' - it could!

Why do people write virus programs? Usually it's for the same reason that people vandalize telephone boxes and daub slogans on walls - it's either stupidity, a strange sense of humour, a chip on the shoulder, or a combination of all three.

How much of a risk is there as far as the average musician goes? Much depends on individual circumstances but it's worth remembering that computer viruses have, from time to time, been discovered on virtually every home and small business computer that is used to run MIDI software... the Atari ST range, IBM's PC and its clones, the Commodore Amiga, Apple's Macintosh etc., have all been the subject of virus attacks in one form or the other.

Given that such a potential threat exists is there anything you can do? Fortunately yes, it's fairly easy to create a situation where you effectively become part of a 'low risk' group.

Prevention

There's no doubt at all that prevention is the best policy. This essentially means minimizing the risks of exposure to virus programs. Almost all common micro viruses have been spread by either 'hacker groups', i.e. groups of computer enthusiasts who spread pirate copies of programs, or by the use of 'public domain' software (i.e. software that is circulated for anyone to use). Most people who write public domain software do not write virus programs - it's just that software which is circulated in this uncontrolled fashion is a lot more susceptible to picking up virus programs along the way. Programs which are 'downloaded' from bulletin boards are another major source of virus propagation.

How do you minimize the 'virus risk'? Firstly, don't use pirated software - for a start it's illegal and if your sense of fair play doesn't deter you... the prospect of getting a virus into your system should! Secondly, if you use any public domain software or if you ever occasionally buy and use secondhand programs, or if you are occasionally given the odd disk from an unknown source then be very careful. Nowadays commercial 'virus protector' programs are available for most common micro-computers. Often they can be installed as part of the computer's initial start-up sequence and, once present, will check all of your disks for known viruses and tell you if anything odd is found. They are not foolproof but if you frequently use disks of unknown origin they're a worthwhile investment.

When you purchase your MIDI software keep your program disks 'write protected' as far as possible. Viruses cannot perform magic - if your program disks are write protected then a virus won't be able to duplicate itself onto those disks. Data disks have to be write-able so these obviously remain vulnerable.

Recognition

Keeping things in perspective we should point out that, providing you avoid the high-risk areas that we've mentioned, you would have to be very unlucky to see a virus program. The tell-tale signs, prior to anything more serious occurring, are unusual disk activity, data disks suddenly becoming 'boot-able', odd program behaviour, and programs taking longer to load than is usual. Occasionally you might see an unusual message displayed... 'This Program is Alive' etc., or you might notice that a program or data file has mysteriously changed size. It's extremely rare, but it is just conceivable, that the first sign you get is when your computer mysteriously crashes and your find that you've lost programs and data. At the present time however please bear in mind that most computer crashes are not caused by virus programs.

Cure

The difficulties of curing a virus attack are two-fold: firstly you have to identify the disks which may contain the virus and secondly you have to work out how to destroy the virus itself. Cures range from simple procedures, such as re-installing a floppy disk or copying files from an infected to a non-infected disk - right up to situations where it is necessary to carry out long winded and detailed investigations of the command files and system utilities present on a hard disk system.

What can the non-expert do? It's fairly easy to use a proprietary virus checker program to identify which disks or programs may be infected but other than that there is little that an ordinary computer user can do - more technical investigations are the domain of the experts and even that path cannot always guarantee success. By far the best policy is to be a pessimist - minimize the risk of exposure and, hopefully, you'll remain one of the many thousands of musicians who will never see a virus program!