In the first article of this series, I covered some of the tools and techniques that users and administrators can apply to remove spyware and other unwanted software. However, an ounce of prevention is worth a pound of cure, especially when it comes to spyware. It's much more effective and much less stressful to keep spyware off systems by preventing infection in the first place. This article will show you how to set up those spyware defenses.
Essentially, there are two ways that unwanted software invades a system: Either the software exploits some sort of security hole and installs without any user intervention, or the software installs with permission from the person at the keyboard, often using varying degrees of using trickery or deception. The second method user-assisted invasion is much more common.
For example, a Web site may imply that users cannot view the site's content until they agree to install an ActiveX control. In reality the ActiveX control is unrelated to the site and only installs spyware. (Users that visit the site with browsers that don't support ActiveX, such as Firefox, don't see that message, but have full access to the site's content.) In other cases, the software may emphasize the benefits ("fun Web icons!") but play down the drawbacks ("endless popup ads"). If you're in doubt about a site, a Google search can often reveal a lot about the software, the company, and their motives.
This site implies that you must install Zango adware in order to run a software product. (Click to enlarge image)
Short of simply recognizing when something is spyware, there are a number of ways to keep more devious forms of spyware off systems. What follows are are few of the more effective.
One of the most important steps that system administrators and users can take is to keep Windows and applications patched. Most major software vendors try to stay ahead of the bad guys and issue regular patches to prevent security problems. In particular, patches to Microsoft Windows and Microsoft Office, which are frequently targeted by malware writers, are critical to keeping a system free of spyware and other unwanted software.