Escape the Spyware Nightmare

Spyware and adware are the newest threats to connected PCs. Here's how to get them off your computer--and keep them off.

Scott Spanbauer

Is your PC feeling sluggish? Has your browser recently acquired a mysterious new toolbar? Are new programs showing up unexpectedly in your system tray? Do advertising windows pop up even when you're not browsing the Web? Have you discovered surprise 900-number charges on your phone bill?

All of these are telltale signs that your computer is beset with adware, spyware, or other malicious software you don't want and don't need. Like viruses, these programs often sneak onto your PC by piggybacking on a downloaded program, e-mail message, or Web site. Though not as dangerous as viruses, adware, spyware, and other unsolicited software can slow your PC, bog down your Internet connection, reduce your productivity, and jeopardize your personal privacy.

You can avoid installing unwanted software by being choosy about the free programs you download, and by understanding your browser's security settings. Removing adware and spyware can be tricky, but several free utilities detect and remove hundreds of known nasties.

How Did This Get Here?

Adware is any kind of software that, once installed on your PC, pops up browser windows containing advertisements. The software may also track your Web browsing (without attempting to identify you personally) and use the information to send targeted advertising related to your browsing habits. While this is fairly innocuous behavior, you are nevertheless paying for these ads to be displayed by donating your machine's processor time and your Internet connection's bandwidth.

Spyware is like adware, except that it has gone completely over to the dark side, scanning your hard drive for personal information or attempting to link your surfing habits to your name or e-mail address. Once spyware has discovered your e-mail address, an onslaught of spam can't be far behind. More insidious than either adware or spyware are dialers, which highjack your Internet connection and silently route you through toll numbers that can cost several dollars per minute. Dialers often piggyback on the porn spam that plagues most e-mail in-boxes. Simply previewing the e-mail message can, in some cases, install the dialer.

Most adware and spyware come bundled with popular free programs, notably the popular peer-to-peer file-sharing programs like Kazaa, IMesh, and BearShare. Installing one of these can dump dozens of additional programs on your PC. Unfortunately, the makers of the host programs try not to advertise their programs' hidden payloads. Reading the licensing agreement (carefully) during installation will often reveal embedded licenses for the piggybacking adware. Look for notorious adware and spyware names like CommonName, FavoriteMan, GAIN, New.net, and "nCase." For an extensive catalog of the many varieties of adware and spyware currently in circulation, see the section on parasites at Andrew Clover's Web site.

Remove the Parasites

You may, in some cases, be able to opt out of installing adware or spyware elements by unchecking a box during installation. Often, this will allow you to install the free program you do want, without installing the undesirables. Frequently, however, bundled adware or spyware installs silently, and offers no uninstall link or tool.

To clear your computer of adware, spyware, and many other pesky programs, use a free anti-spyware utility like PepiMK Software's Spybot Search & Destroy or Lavasoft's Ad-aware 6.0. In fact, you may have the best results if you use both, since neither is likely to catch every malicious application installed on your PC. Neither program detects or removes viruses, so you'll still need to use a good antivirus program, such as Symantec's Norton AntiVirus 2003 ($50; $15 annual renewal fee).

And be forewarned that many programs that include spyware or adware won't work after the spyware is removed. In such cases, you'll need to find a (spyware-free) replacement. Webroot, maker of another good anti-spyware tool called Spy Sweeper, offers Spy Audit, a free online spyware scan.

For a more in-depth review of both antivirus and anti-spyware tools, see "Pest Zappers."

Staying Clean

Once you've cleansed your PC of unwanted programs, you can keep it clean by avoiding spyware-laden downloads and by upping your browser's security settings to avoid "drive-by" installations. Internet Explorer is the main target of most of these, and its default setting (Medium) will prevent automatic installations of most Web-based adware and spyware.

To check your browser's settings in IE, select Tools, Internet Options, click the Security tab, and choose the Internet zone. Make sure that the security level setting is at Medium or higher. In AOL 8.0, which uses IE to display pages, choose Settings, Preferences, click the Internet Properties (WWW) link, then select the Security tab, and choose the Internet zone to access the same settings options as IE.

With your Medium (or higher) setting, however, you'll still be prompted to install software that may appear safe. As a rule, don't accept any downloads from sites you don't know and trust completely. See "Internet Tips: Play It Safe With the Right Browser Security Settings" for more detailed tips on securing IE, Netscape, and Mozilla against Web-based threats.

Unfortunately, there's no sure way to know if a program contains spyware. Reviews, the maker's Web site, close examination of the installer and license agreements, and the experiences of other users are your best bets for solid information; try Google for a fast way to find all of these. If you think a program may be safe, go ahead and install it, but be sure to scan your PC afterward with an up-to-date anti-spyware utility, or even two. You can't be too cautious.

Scott Spanbauer is a contributing editor for PC World.