Spyware Exposed

Maggy Sterner, NPR Online

Some Web companies offer free programs -- day planners, clocks -- in exchange for information about users' Internet habits.

Increasingly on the Web, the burden is on users to know what they are agreeing to.

See an example of an ad masquerading as a security alert.

Ever seen that green alligator that offers -- for free -- to keep your computer clock synchronized with U.S. Atomic Time? Or how about that cute purple monkey who offers to track appointments? If you have either of these on your computer screen, you also have spyware. It's a class of stealth software programs that can do everything from sending you targeted pop-up ads to recording your passwords. NPR's Susan Stone reports.

According to one study, spyware has infiltrated millions of computers. Spyware can be as innocuous as a program that monitors what Web pages you visit, or as aggressive as a program that can hijack your Web browser and send you to sites without your permission. Some spyware may even come bundled with a type of virus called a "trojan horse" that can take over your computer.

In general, any technology that gathers information about you without your explicit permission is considered spyware. A look at some types of programs that may be spying on you:

Adware: Some software applications track where you go on the Web, report the information back to advertisers, and then allow advertisers to target you with relevant ads. This type of adware often comes bundled with a free program you're downloading, such as clocks, weather forecasts or programs that offer to remember information -- such as your address, passwords, phone numbers -- and fill out forms for you. In exchange for the free program, you're trading information about you and your browsing habits. Most of these programs tell you what they're doing in the fine print on their user agreements. Surveys show, of course, that most people don't read these agreements.

Cookies: Many Web sites have "cookies" -- a file that downloads to your computer when you visit a site. Most cookies are innocuous, or even helpful. Companies read cookies that they've placed on a user's computer to help them find out information such as what pages were visited. For example, NPR uses cookies to remember a user's member station or what audio player is preferred. But some cookies can be used to help gather more information than you're comfortable sharing.

Driveby Download: A software program that is automatically saved to your computer when you visit certain Web sites. Most of these programs are spyware. Programs that actively change your homepage and other browser settings to take you to Web sites you had no intention of visiting often are delivered by driveby downloads.