Arguably, you don’t have to know viruses inside and out to avoid getting them out.

It really makes little difference, whether it’s a trojan keylogger that’s got you in it’s grips, or a virus, the effects can be as nasty.

What computer users should appreciate is that there are lots of people out there who want to attack your computer, disabling it, or rob you of your hard earnt money.

Let’s take a look at the line-up of nasties.

First up are malicious web scripts and code. These are bits of code which are designed to make your life hell. They might come in the form of ActiveX controls and they have a number of tricks, including installing spyware on your system, stealing personal information and deleting files.

ActiveX controls are beloved by Internet Explorer, and only them, so, if you don’t want to take the risk, upgrade your Internet Explorer version (7 and 8 have better safeguards), or use a different browser such as Firefox.

Now, next in the line-up are for some quite innocent little things. Cookies are more sneaky, than dangerous, and without them, many of the sites you might use on a regular basis, wouldn’t be so convenient. But bear in mind that cookies are effectively trackers of your behaviour and choices. And they are often used to report back to their owners a lot of information about you. So, if this sounds intrusive, don’t encourage them.

Next up are pop-ups. These might sound like innocent critters, but avoid them. Pop-ups are little ads which can quickly clutter up your computer as they appear and disappear at their choosing. And although many of them might be innocent, quite a few are used as carriers of nastier things, such as spyware, so get rid of them pronto. Use a pop-up blocker, or, if you’ve got Windows XP with Service Pack 2, or Vista, then they have pop-up eradicators.

Malware has a wide range of definitions and sub-groups, although what makes this subject confusing, is that different groups of people use different labels and explanations. But, generally, the main types of malware are: spyware, adware and home page hijackers (or browser hijackers).

Spyware literally spies on your computer. It might do that covertly, or overtly, creating pop-ups, or downloading so many applications onto your computer, that it slows your machine down to a snail’s pace. It also grabs usernames, passwords and bank details, sending them back to its creator.

Adware is often the price you pay for free software applications. But it’s simply not worth it. Unless you can swear by the source of the free software and trust its credentials, don’t be persuaded from the true path. Being cynical and doubting is one of the best features of a sensible surfer.

Adware gets itself installed (often as a trade-off for free goodies), then targets ads at you. But these ads are targeted because if you visit a certain site, lets say on dog leads, then it will send you dog lead adverts.

You can see the logic, but it can get quite tiresome keep getting dog lead adverts, especially when you’ve bought one, and these adware programmes are tracking your surfing habits and can be selling that information to other companies, so that they too can send you ads. Resist the adware temptation; don’t do it, because eventually a dirty piece of code will wheedle its ways into your computer and it won’t be a very enjoyable experience.

Home page hijackers are just that. It’s a programme that resets your home page to its choice, not yours. And when you change your setting back to your own home page, the hijacker changes it back again. And once it’s done that, it sends you pop-ups and can even re-direct your searches. Hijackers generally don’t have a good press, and these certainly don’t, so be on your guard against them.

Malware is usually infiltrated on your computer as part of downloaded applications, or picked up from a ‘dirty’ website, or on the back of a pop-up.

Now, malware is pretty evil, but the next bunch of villains in the line-up, come pretty close.

Trojan Horses and back door programmes are aptly named. They secretly get into your system and start doing things that you are mostly not aware of until its too late. But they have the same effect as someone sitting at your computer and using it themselves. They enter your system via a software download, or in the same way that spyware infiltrates systems.

A particularly nasty Trojan is what’s known as a keylogger. And, as with most of these things, it’s all in the name. A keylogger records your keystrokes and sends them to the person controlling the trojan. And by logging your keystrokes, they can work out your usernames and passwords etc, effectively then they are able to access say your bank accounts with the same information. Not a pleasant thought.

Viruses have the distinction that of being the generic term for all the nasties we are mentioning here. The true definition of a virus is a piece of software that is invisible and infects your computer by copying themselves onto your applications. And once into your system, it has a number of amusing little tricks for your edification. It might crash your computer, wipe your hard drive, or delete files. Their favourite way of getting in, is within an email attachment.

Now, you avoid these by computing with sense. And you do this by delegating the job to the best anti-virus software you can afford. This will allow you to stop getting a dirty computer.

Windows XP and Windows Vista do have safeguards, and you should always update the security patches, but you should not rely on those alone. It is generally better to purchase an anti-virus protection suite which properly protects your computer against known and future viruses. And this is key. New viruses are invented daily, so you need to use a protection suite that updates itself on a regular basis, and recognises viruses that have just been written and sent out.

So, get yourself the best protection you can afford and be careful out there; it’s a jungle.

Understanding Viruses & How to Avoid Them – Recap

• watch out for bad ActiveX controls;
• malware comes in three main forms;
• trojans bad;
• viruses bad;
• XP and Vista need help.