Spyware under the microscope

Persistent pests
There's one particularly persistent type of spyware that is more common, however, and can be really hard to get rid of. Any software that is installed on your PC, whether spyware or something useful, adds information to the Windows Registry.

The Registry contains information about all the software installed on your PC. Each time a PC is turned on it checks the Registry and uses that information to set itself up properly.

If a spyware program has been added to the Registry the PC will automatically run the spyware software each time the PC is turned on. Ordinarily, when a program is uninstalled, its entry is also removed from the Registry.

However, some spyware programs cleverly install a secondary program that can monitor the Registry. If the main spyware program is uninstalled along with its entry in the Registry, that secondary program will detect this and reinstall the spyware again. The secondary program is also listed in the Registry, so a more thorough clean-out of this file can eliminate this problem as well.

Very experienced PC users may want to delve directly into the Registry themselves but this is very tricky and we don't recommend it for most. Fortunately, there are a number of easier options. The simplest option for those using Windows XP is to use its System Restore function (listed under Help and Support in the Windows Start Menu).

The System Restore command allows you to make a record of important settings on a PC, including the contents of the Registry, and save them in case anything ever goes wrong with the PC.

So if you suspect spyware or adware has been installed on your PC you can use System Restore to quickly revert to an earlier version of the Registry and remove all the new software. Both Ad-Aware and Spybot create System Restore points automatically.

If you don't have Windows XP you can still use programs such as Spybot to try and clear out both the spyware and its associated secondary program. There are also specialised programs, such as Registry Mechanic, designed to scan your Registry and detect potential problems.

They can also help you to save a backup copy of the Registry. In the event of an emergency you can use the backup Registry to replace the current Registry.

As always, though, prevention is the best cure, so it's also worth looking at ways of preventing this software from getting onto your PC in the first place.

Update and protect
Our first piece of advice is to use the Windows Update feature built into Microsoft Windows to download all of Microsoft's recent security updates. Windows XP users will find a little Automatic Updates icon in the Taskbar, down in the lower right-hand side of the screen.

Anyone running Windows XP on their PC should also download Windows XP Service Pack 2 (or SP2 as it's also known). This adds a long overdue pop-up blocker feature to the Internet Explorer web browser, which detects adverts as they start to appear on screen and stops them in their tracks.

If you're not using Windows XP there are alternative pop-up blockers that you can download for free, such as PopUp Stopper, which is available on the Computeractive website. If a pop-up window does appear, never click on it. To close it safely, hold down the Alt key and press F4.

Aside from Ad-Aware and SpyBot, which we mentioned earlier, there are other programs that can be used to fight back against spyware. Microsoft is currently testing Windows AntiSpyware, which is already free to download and try out.

All the anti-spyware tools that we've looked at so far are free but most of the companies that sell commercial anti-virus software have also added anti-spyware products to their range.

Symantec sells the Norton Internet Security suite, which combines anti-virus protection with spyware detection, and McAfee sells a dedicated anti-spyware program - McAfee Anti-Spyware - for £25.

Our main piece of advice would be to make sure that you don't just rely on one single program to protect your PC. There may be spyware programs that are missed by one program but will be picked up by another, so it's worth having at least two anti-spyware programs on your PC to make sure that you're safe.

Fight back
At best, spyware and adware pose a threat to your privacy and at worst to the safety of your personal or financial data. The chances of your PC becoming infected with spyware capable of capturing online bank account details or passwords and that information being used successfully to drain your account are slim. Nonetheless, spyware poses a threat that most of us would rather live without and adware can cause enough of an irritation to hamper your use of the home PC.

Thankfully, though, there is a good range of tools available - many for free - that can scan for malware and remove it from your PC. Our first advice would be to download Ad-Aware, SpyBot or Microsoft AntiSpyware to help clear out the worst offenders.

Secondly, make sure your PC is up to date with all the latest Microsoft security updates and get into the habit of scanning for spyware once or twice a week, depending on your internet usage. You could also try using a non-Microsoft browser such as Opera or Firefox. These aren't immune from spyware but most malware exploits flaws in Internet Explorer.

Like any other security threat, it's best to take spyware seriously but there's no reason to panic: with the information contained in this feature under your belt, you should be able to protect yourself effectively.

Hanging on the phone
There's a particularly unpleasant type of malware known as a dialler. If you're using a dial-up internet connection rather than a broadband connection, these programs can take over your PC and alter its internet settings without your knowledge.

Instead of dialling the number of your normal internet service provider, the dialler will connect to the internet via a premium rate telephone line, which means you get landed with a huge phone bill.

There is an organisation called ICSTIS (Independent Committee for the Supervision of Standards of Telephone Information Services) that acts as a watchdog over these sorts of telephone scams.

Unfortunately, it can take months to investigate complaints about dialler programs, and even then you may not get your money back, even though this scam really is no better than outright theft.

The best way of dealing with diallers is to strike first. If you're using a dial-up internet service, should contact your telephone company and instruct it to block access to premium rate numbers. Microsoft's AntiSpyware program is also useful, as it warns if a dialler is about to try and install itself onto your PC.