Malicious websites may attempt to install spyware on readers’ computers. In this screenshot a spamblog has triggered a pop-up that offers spyware in the guise of a security upgrade.

In the field of computing, the term spyware refers to a broad category of malicious software designed to intercept or take partial control of a computer’s operation without the informed consent of that machine’s owner or legitimate user. While the term taken literally suggests software that surreptitiously monitors the user, it has come to refer more broadly to software that subverts the computer’s operation for the benefit of a third party.

Spyware differs from viruses and worms in that it does not usually self-replicate. Like many recent viruses, however, spyware – by design – exploits infected computers for commercial gain. Typical tactics furthering this goal include delivery of unsolicited pop-up advertisements; theft of personal information (including financial information such as credit card numbers); monitoring of Web-browsing activity for marketing purposes; or routing of HTTP requests to advertising sites.

As of 2005, spyware has become one of the pre-eminent security threats to computer-systems running Microsoft Windows operating-systems (and especially to users of Internet Explorer because of that browser’s collaboration with the Windows operating system). Some malware on the Linux and Mac OS X platforms has behavior similar to Windows spyware, but to date has not become anywhere near as widespread.

Links

Guides

• Magoo’s Guide to Eliminating Spyware — Information on how to get rid of spyware and keep it from returning
• CareOfWindowsXP Spyware guide — Advice on spyware for beginners
• Spyware & Malware Removal Self-Help Guides — Self-help guides on removing different types of Spyware and Malware.
• Protection against Adware and Spyware – Beginners guide to preventing the installation of spyware

Prevention

• How Spyware And The Weapons Against It Are Evolving — Article discussing causes and possible remedies of the spyware problem
• “Using Virtual Machines to Defend Against Security and Trust Failures”
• SiteAdvisor – SiteAdvisor – free software to alert users about sites that install malware or otherwise breach security
• ShieldsUP! – ShieldsUP! internet vulnerability test, can detect a system’s weaknesses such as open ports that may allow malware entry

Organizations

• Anti-Spyware Coalition — A group developing formal definitions and best-practices
• StopBadware.org – A non-profit group (sponsored by Google, Lenovo, and Sun) that aims to provide “reliable, objective information about downloadable applications”.

Software

• http://www.lavasoft.com Ad-Aware antispyware program, free version available
• Safer Networking Spybot Search & Destroy and other free security programs

This guide is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.

Video: Computer Virus, Spyware.