Best Defenders

Eye on Behavior

Many anti-spyware products try not only to clean up known spyware but also to prevent as-yet unidentified spyware from landing on your machine. To do this trick, they monitor areas of the system that malicious software targets, identify suspicious behavior, and stop it. To evaluate such behavior-based capabilities, we created an app to perform actions indicative of spyware and adware installations: adding Registry run keys, adding a file to the Windows startup folder, changing the browser start and search pages, and overwriting the Hosts file, the first place that Windows goes to look up Web addresses you want to access. Spyware can modify the Hosts file to redirect you to certain sites (like adware servers) or prevent access to others (like antivirus-company sites).

CounterSpy, McAfee, Spybot, Spy Sweeper, Spyware Doctor, Windows AntiSpyware, and the ZoneAlarm suite all offer some behavior-based protection. Spy Sweeper proved to be the most effective. For more details on how these features stacked up, click here.

When it came to ease of use, Panda's suite was top-notch, removing detected adware and spyware without relying on user input. You can also change the default settings to allow case-by-case decision-making. The ZoneAlarm suite displays many alerts that demand your response, which can be challenging if your knowledge of security isn't thorough.

We were also less than impressed with the McAfee interface. The icon that appears in Windows' system tray doesn't launch the anti-spyware scanner; instead it launches the McAfee SecurityCenter, which advertises other McAfee products but doesn't include McAfee AntiSpyware.

The Battle Continues

As we said, spyware keeps changing, and so do the tools that fight it. Around the time you read this, five vendors--Sunbelt, Symantec, Webroot, and Microsoft--plan to update their software. As new releases appear, we'll pit them against the newest and nastiest threats. Check PCWorld.com's Spyware and Security Info Center for ongoing coverage, including reviews, news, tips, and downloads.