What is Spyware?

Spyware represents a new type of malware that poses a signifi cant threat to business and home users. Unlike those who create other forms of malware, such as viruses, spyware authors are not motivated by curiosity or a desire to establish a reputation. Instead, they are attracted to the possibility of making large amounts of money quickly and easily.

In general, spyware describes a category of software designed to capture and record confi dential information without a user’s knowledge or consent. Key loggers, as discussed in chapter three, are a typical example of spyware. Some Trojans can also be classifi ed as spyware.

Applications for spyware range from monitoring the actions of a spouse to industrial espionage. Although early spyware programs were quite primitive, modern applications have a number of sophisticated features that make them diffi cult to detect and remove. Like viruses, the most advanced programs are able to disable or delete security software, and some even pose as spyware removal tools. Spyware can be grouped into a number of categories, including the following:

• Data miners: Programs that collect information about a user, supposedly with his knowledge and/or consent. Spyware developers sometimes justify the use of such software by referring to the use of clickthrough agreements.

• Monitoring tools: Software intended to report on a user’s activities, including the use of Trojans and key loggers.

• Trackers: Programs that monitor Internet activity, recording information such as the sites visited by a user. Trackers do not necessarily record personally identifi able information.

• Annoyware: A type of adware that attempts to force advertising on users by opening multiple browser windows, pop-ups, and so on.

• Browser hijackers. Sometimes called home-page hijackers, these programs hijack the user’s home page and can also make other changes, such as changing the default search engine or altering system settings.

• Dialers. A type of program that alters the settings used to make dial-up connections to the Internet, usually with the aim of calling premium rate numbers at the expense of the user. The numbers called are often linked with services that provide pornography, causing some people to become too embarrassed to make a complaint.