What Is Spyware, Anyway?

Spyware is software or a software configuration that gathers information about a person or organization without permission or knowledge. Spyware does this often by just peeking, but other times, it spies by changing the configuration of the victim's computer.

An information collector

Spyware can collect information from a user's computer and periodically transmit it to a specific location — usually a server someplace. The method used to collect information may be a built-in feature of the Web browser, a downloaded ActiveX control, a Web browser plug-in, or a standalone executable program.

The type of information collected by spyware may include the following:

Tracking Web sites: You may have heard the term adware, which many consider as a subset of spyware. Marketing companies and banner ad providers (many of which are totally legitimate companies) use adware solely to track which Web sites a user visits and whether the user patronizes banner ads. Such information is generally used by marketing companies, which are always trying to separate folks from their money. Some spyware may do more than just track Web site visits, however.

Logging keystrokes: Among the diabolical types of spyware are key loggers, vile beasts that actually record every keystroke on a user's computer and transmit them to a hacker's lair. Users who perform online banking and other electronic commerce on computers with key loggers are bound to have their highly sensitive user IDs, passwords, credit cards, and bank account numbers recorded and sent to unsavory individuals.

An information transgressor

Spyware can alter information on a user's computer, such as the browser's default home page, search page, and the HOSTS file (a text file that contains the IP addresses corresponding to specific host names).

Among the types of spyware that change information on your computer is scumware, which is a term describing browser plug-ins that alter the appearance of Web sites, often substituting the Web site's banner ads with its own ads. A Web site might include a banner ad that takes viewers to the Web site owner's Amazon.com affiliate pages, for instance, but the scumware inserts its own banner ads (and those of its advertisers) in place of those that the Web site intended the viewer to see.

Scumware also creates hyperlinks within the text of Web pages that take users to advertisers' pages. For instance, a user may be viewing a Web site for a local merchant. The scumware inserts hyperlinks on certain keywords on the merchant's page (as viewed by the user whose PC has the scumware installed) that lead the viewer away from the merchant's site, perhaps leading to competing Web sites. Usually an ActiveX control, scumware alters the content of a Web page, and it does so by changing (in real time) how the user's browser displays the page.

If you search for instructions for removing spyware, make sure you are following accurate instructions on a trusted Web site.