Programs that secretly record what you do on your computer are called spyware. They can be used for some perfectly legitimate purposes, but the majority of spyware is malicious. Its aim is usually to capture passwords, banking credentials and credit card details - and send them over the internet to fraudsters.
‘Spyware’ is the generic name we give to programs that contain additional functionality designed to secretly monitor your activities on your computer.
The aim of spyware
Some of the earliest spyware did little more than report to the authors each time the program was used. It was intended as a marketing aid or to monitor usage for licensing purposes.
That still goes on, but a lot of spyware nowadays is designed to steal confidential information - user names and passwords for banking sites, email accounts, social networking sites and online games.
You may never know you have malicious spyware on your computer, as it tends to work quietly in the background and the overt functionality and quality of the program may be very appealing. They're often distributed as 'shareware' or 'freeware' with minimal license restrictions in order to trap as many people as possible.
How to protect yourself
There are several ways that you can protect yourself from spyware. Firstly, don’t unwittingly install it. Many shareware download sites now test programs submitted to them and offer guarantees that their archives are free of spyware.
You have to take this on trust, but the more established sites have their reputation to maintain, so their guarantees can usually be relied upon. So it's a good idea to download only from reputable software sites, however tempting the offers may be from less well-known ones. Reviews of download sites can help you decide which are the safest.
Secondly, you can install an anti-spyware tool. Many of these are of high quality, and some are freeware themselves. These tools regularly download updates to stay abreast of newly- emerging spyware. Some of them can run in the background all the time, without really slowing down your computer, and they generally do a very good job.
Beware dangerous imposters
But there are also some malicious programs that masquerade as anti-spyware and anti-virus tools. These are often advertised in spam emails or occasionally on the phone, and are very dangerous. They are generally used for extortion.
Typically, they either encrypt your hard disk so you can't read your data, or keep popping up in nagging windows so you can't work on your computer. Then they demand money to release you from the problem, but there's no guarantee that paying up will result in a fix. So never trust an unsolicited offer of anti-virus tools or anti-spyware - it's probably fraudulent.
You can tell which tools are the most genuine by searching the web for reviews of anti-spyware products. A few names will frequently come up as having a good reputation, and these are the ones to choose from.
Exceptions to the rule
There are some legitimate uses for spyware. If you have a work laptop supplied by your employer it might have a kind of spyware installed.
Some sensitive businesses like to keep tabs on the computers their staff use, and there are mainstream products which perform this function. But you should be made aware of this as part of your contract of employment, or at least in your staff security policies.
Spyware of a sort is also used for parental control programs that protect children from unsuitable internet content.