HOME BUILDERS ARE NOT KNOWN FOR their affinity for computers, but they still need to care enough to protect their machines from spyware, an insidious type of software that can invade a computer without a user's knowledge and create all kinds of confusion and unpleasantness.

The problem is a common one. Many builders we've talked to have experienced serious slowdowns or have had to scrap their computers altogether because of spyware invasions. Even some of the most tech-savvy users were unaware of the issue and unsure how to guard against such attacks.

The Gartner Group, a leading information technology consulting company in Stamford, Conn., defines spyware as software that spies on a user's Web activities through a combination of cookies (software that lets Web sites keep track of users and their preferences), files, and processes that are placed on a user's PC through a browser such as Microsoft's Internet Explorer. The spyware then reports this information back to Internet sites and often interferes with the user's browsing experience. In numerous cases spyware so thoroughly infects a user's PC that the machine becomes unusable or even unfixable.

The truth is that anyone browsing the Internet on a personal computer with Internet Explorer is a potential target. Most spyware seeks to exploit vulnerabilities in Microsoft Windows and Internet Explorer, the most popular operating system and browser, respectively, and the low-cost computing options used by many home builders. Mac users are not immune, but they are much less vulnerable.

According to the Spyware Research Center managed by Giant Company Software, in Redmond, Wash., spyware ranges from adware, covertly installed by online advertisers, to extremely malicious key loggers, which record all the keystrokes made by a user. Adware can generate a stream of unsolicited ads and pop-ups that can clutter a PC desktop and affect productivity. The goal of the key logger, meanwhile, is to steal credit card, bank account, and other personal or corporate financial information. Browser hijackers—intrusive programs that change a user's Web browser settings, altering designated default start and search pages—are also a form of spyware.

“It got really bad about five or six months ago,” says Geoff Meiteen, president of Master Builder, a custom home builder in the Austin, Texas, area that depends on three stand-alone PCs in a home office. “We got inundated to the point where our systems couldn't function, so we brought someone in to run sweep software.”

Meiteen says he paid about $150 to have a local information technology (IT) consultant clean out the system. Now, Master Builder uses shareware (free software available on the Internet) from Spybot Search & Destroy and Lavasoft's Ad-Aware 6.0 to help manage spyware. The company also added Norton Internet Security, which protects the company from common viruses, spam, and hacking attacks.

Some other builders have taken action as well. John Pizzo, a consultant who manages information technology for Artery Homes in Bethesda, Md., installed Spybot Search & Destroy shareware on all of the company's 50 PCs.

“The best way to think about it is this is where we were with viruses a couple of years ago,” says Pizzo, adding that when an Artery computer user complains that a computer has slowed down or is inundated with pop-up ads, the anti-spyware shareware does a good job of identifying and cleaning out the files and programs that don't belong.

“For the most part, the Spybot protects the users pretty well,” Pizzo says. “We're kind of on a budget, so for now, this works well.”

Learn more about markets featured in this article: Austin, TX.