While a human virus like Flu can cripple your business if it spreads through your employee base, a computer virus can literally kill your business, yet there is much more you can do to protect and in the main resist computer viruses but too many people ignore the threats.

The term computer virus is actually fairly wide in definition but effectively covers programs (some large, some simple lines of code) that change how your computer works. That might mean actual damage to the components or – and a potentially greater risk for a business – making the computer do things that the owner didn’t intend. Usually a virus also has a built-in ability to self-replicate too helping it spread its destruction quicker.

There are three types of virus:

True Virus

A true computer virus infects not the hardware of your computer but the software you already trust. That means piggy-backing itself to a host program on the machine. Once infected, each time that program runs the virus runs too . The ‘Melissa’ Word document is probably the most well-known of this type – replicating itself to the top 50 people in the unlucky recipient’s email account, with a message “Here is that document you asked for, don’t show it to anybody else”. Be aware too that you don’t need to double-click the attachment to spread the virus. In many cases just appearing in the preview window will be enough.

Worm

Just like the animal that gives it its name, a worm finds holes and moves into them. A worm is a stand-alone piece of software that exploits security flaws and uses them as a route to replicate itself. Worms scan computer networks and dive into the holes they identify, replicating itself on the receiving machine and then beginning the replication process again.

Trojan

Named after the Greek classical trojan horse, a computer trojan is a program that has similar deceptive tendencies. Claiming to do one thing but really do another. The most common trojans truly live up to their name by effectively creating a back door into a computer that can be exploited by remote user. Other trojans may cause physical damage, perhaps to a hard drive, or . Some might damage a victim’s hard drive.

Pretty much all viruses have a multitude of functions. Some are even disguised as helpful programs that will do a job for you while creating back door access for hackers or spying on your PC usage and sending the information elsewhere. Usually without replicating functions, this kind of ‘malware’, has become an increasing threat, with those behind them running elaborate business schemes that uses the information gleaned or scammed from the infected end-user.

Viruses are nothing new

They actually pre-date the internet. The first virus was launched 30 years ago when in 1971 the ‘Creeper’ virus was launched ‘under control’ by one of the technicians working on building ARPANET, the Internet’s ancestor. Much like the modern day worm, the Creeper looked for a machine on the network, transfers to it, displays the message “I’m the creeper, catch me if you can!” and then replicated itself.

A very real threat

The biggest problem with computer viruses is that they don’t go away and every day new ones are added via the internet increasing the risk. Of course older viruses are usually easily detected and dealt with by modern anti-virus software but the threat is still there and those writing the virus programmes are as up to date with new technology and opportunities as anybody in the IT field. An interesting insight into the threat of security risks can be seen on Symantec’s Security Response website, where you can see what viruses are spreading quicker, etc. The last report from Symantec themselves which examined security threats in 2011 suggested that web based attacks increased by 36% in 2011 alone with over 4,500 new attacks each day.

So what can you do protect your business

The biggest defence you can provide is ensure that every machine attached to your network is running up to date virus protection. There are countless options out there all geared at doping the same job of protecting your systems but the key is making sure they stay up to date. Make updates automatic, but also make checking that software is up to date as part of your regular housekeeping.

Include in your scheduling not only updating of your anti-virus software but also updating of all your software. Many viruses replicated due to security flaws identified in popular programs. Software manufacturers are constantly battling to cover and close all these potential holes and usually issue these as ‘patches’ or updates and you should always make sure you keep these up to date too to minimise the risk.

In addition you need to be savvy in your use of your machine. Smartphones and tablets can be affected by viruses too so don’t think it is limited to your desktop machine. Malware can also infect your website, so make sure you protect that too with a system like SiteLock.

Be wary of what you click on, especially what you download. Is it from a trusted source? Do you know the full implications of what this piece of software might do? If you are concerned don’t click on links and don’t download files. Know who and what you are dealing with and you are less likely to be caught out.