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Stopping spyware

Who's watching you? Keep your computer spyware free

According to a recent report that surveyed over a million internet-connected computers, your PC is likely to be infested with around 28 programs that have been installed without your knowledge. Welcome to the world of spyware and adware.

Most of those programs will be more or less harmless. ‘Adware’ fetches advertisements from their host website and pops up the ad from time to time on your computer or installs a toolbar of some kind on your desktop.

‘Pop-ups’ are their equally irritating siblings – you visit a website and a small window unexpectedly pops up with a sales message of some kind. You didn’t ask for it, you didn’t click on an ‘open window button’, but it appears anyhow.

A variant of adware is the 'browser hijack', and here something has been installed on your computer. If Internet Explorer starts on an unexpected web page, typically a sales message or an unknown web search, your browser has been 'hijacked'.

This is irritating and intrusive. What’s worse, some adware applications secretly snoop around your computer collecting information such as your browser history. That qualifies them as ‘spyware’. Advertisers are keen to see what kind of web pages and ads you look at so that they can promote the same kind of things directly to you; spyware programs work behind your back to collect that kind of data about your browsing habits.

The same kind of technology can be used to write more malicious programs. These Trojan horses can steal information stored on your PC (including your passwords or credit card details) or provide someone with unauthorised access to your computer.

These programs will put a little extra strain on your PC and they will take up precious memory: if you have a lot of spyware running without your knowledge, the result could be a noticeable slowdown. Adware programs in particular tend to be rather inefficient, so your PC could become susceptible to hiccups and even crashes.

Where do these programs come from? Most spyware is downloaded and self-installs sneakily when you visit particular web sites. You might also inadvertently acquire spyware when you download something like a game or a file-sharing application; the spyware might be installed at the same time as the program you wanted.

Once installed, the spyware will run in the background and can be difficult to detect and remove.

Detection and Removal

At least you can remove them. Specialised utilities such as SpyBot and Ad-Aware, as well as Microsoft's AntiSpyware software can hunt down the spyware in your PC and eliminate it. But as with virus-hunters, they have to know what they’re looking for: so you need to keep the spyware killers current with regular updates.

Prevention: Better than a Cure

The better option is to prevent the spyware getting on your computer in the first place. Windows Service Pack 2 includes upgrades to help you do this.For a start, it warns you when a web site is trying to download files or software to your computer. It can also block pop-up windows.

SP2 also makes sure that Windows Firewall is enabled by default. This means that any attempt to pass information back to a spyware’s host site will probably be detected and prevented.

To cope with spyware, follow these recommendations:

Install Service Pack 2 and make use of it – don’t change the default setting for prohibiting pop-ups, and be very careful if you’re advised that a web page includes potentially harmful features

Only install software from web sites and vendors you trust – and be particularly careful if Windows warns you that they do not have a valid digital signature.

If you download software, check the end user license agreements. Look out for wording that describes information-gathering capabilities; it may mean acceptance of a spyware download.

Use software that detects spyware, and keep it up-to-date.

What next

Our fortnightly security bulletin will keep you up-to-date with the latest threats and developments. Find out more and sign up now.

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