On Test: antivirus software

All responsible PC users know the importance of having up-to-date antivirus and security software installed on their PC. Without it you could lose data, risk having personal details snooped on and your computer could even be used by junk emailers to distribute spam.

Just as the number of potential threats to PC security has increased, so too has the number of antivirus software products on the market, making it harder then ever to choose the right solution.

For many people, the most straightforward way of tackling antivirus protection is simply to carry on using whatever security software came with their PC when it was purchased and sign up for a subscription at the end of the trial period.

However, this isn't necessarily the best solution. Certain antivirus programs may not work with certain email programs, for instance, and may even slow down a PC. And with some ISPs automatically scanning email for you, as well as the availability of free software online, is it even worth paying for antivirus software at all?

What it does
There's little doubt that antivirus protection is an important part of staying safe online, but what exactly does antivirus software do, and how does it work? Essentially, an antivirus program monitors a PC's activity for two things: actions and patterns that may denote the presence of a virus.

The actions that it scans for are things such as unexpected changes to programs on the computer, changes to the contents of the hard disk or an unusually high number of emails being sent. These are all things that could indicate a virus at work.

Patterns, on the other hand, could be contained in files that have been infected with a virus. It might be the message that a virus displays, or a piece of the virus code. Each virus has one or more of these, and antivirus tools detect them like fingerprints at the scene of a crime.

Spotting computer behaviour that indicates the presence of a virus is only possible once a computer is already infected. While this is better than nothing, it's far preferable to be able to intervene before things reach this stage. That means intercepting viruses before they install themselves on your computer.

To do that, you need to look for the tell-tale patterns and, since new viruses are being created all the time, antivirus software needs to keep the patterns it recognises, called 'virus definitions', up to date.

This means downloading the latest virus definitions from a database of updates maintained by the software developer. It's that service that you're ultimately paying for when you buy an antivirus program: the updated files, and the work involved in creating and distributing them.

Choosing your approach
When it comes to actually spotting viruses, antivirus programs employ several different methods and most software will give you the option of choosing what sort of scan to run. For example, since most viruses tend to arrive by email, scanning incoming emails is an important first line of defence, allowing a program to stop a virus before it even ends up in your mailbox.

You can also run a scan of the computer itself, checking every file on the hard disk. Generally, an antivirus program will do this when it's installed and you can then schedule this to happen automatically at set intervals.

As many thousands of files are stored on most PCs, though, this can be time-consuming, so many programs provide a range of 'smart' options that will scan higher risk files only, for example.

If you've ever set an antivirus program to scan an entire hard disk, and then tried to carry on with work while it happens, you'll know how much the computer's performance is affected by the scan.

A virus scan is certainly not something that should be running when you're trying to get on with something else. Some packages do offer a background scanning option, however, which takes longer but won't have such an impact on performance.

Another line of defence is 'on access' virus scanning, which simply checks each file as it's opened, to make sure that it's not infected. So if a file has found its way on to your computer somehow, it'll still be spotted when you try to access it.

Most of the time, all this happens without you realising it, but even if you don't see a serious slowdown of your PC, there's still a penalty associated with keeping an eye on what's happening all the time, as our lab tests revealed.

So, if you thought your PC was running slowly, the culprit could well be the antivirus program that you're relying on for security.

Free protection
Buy a new PC these days and it will most likely come with antivirus software installed, or ready to install, usually in the form of a trial for one of the big name products, such as Symantec's Norton Antivirus. The simplest option, and the one many PC users opt for, is to pay up to continue receiving protection at the end of the trial period.

But with free antivirus software available online, do you really need to pay to get good antivirus protection? When it comes to good quality free antivirus software, one of the most well known is AVG Free Edition from Grisoft. Not only is it free for personal use, but it stands up very well against the paid-for competition.

Among its most important features, AVG provides on-access scanning to make sure you don't accidentally open an infected file that's found its way on to the PC, scheduled scanning of the computer system (so you can arrange for a full scan to be done when you're away from the computer) and checking of incoming and outgoing emails.

There's even a feature that works with Windows Explorer and lets you right-click on a file and choose to scan it. And to make sure you don't forget to keep the software up to date, new virus definitions can be downloaded automat ically, taking just a few seconds over a broadband internet connection. The program download is only 12Mb in size so it's worth it even if you use a dial-up connection.

The program itself is fairly compact, and won't use up too many of a PC's resources. Installation is very straightforward and the program will automatically configure itself to scan your emails and download automatic updates to both the program and its virus definitions.

You'll even be prompted to create a rescue disk to help restore the PC to working order if disaster strikes. Once installed the software can be kept up to date with little effort.

Like this story? Spread the news by clicking below:

 del.icio.us     Digg this     reddit!