Attention network managers: get out your wallets.  If you haven't done so already, it's time to buy and install a good anti-spyware application on your office and home PCs.  The problem with spyware is becoming so pervasive that you need to take action before your individual users do; they could end up doing more harm than good.

"Spyware" is the general term given to software that surreptitiously makes its way onto your computer.  It may also be called "adware," "scumware," "malware," or other equally sordid-sounding names.  No matter what you call it, spyware is an unwelcome intruder in your computing environment.

IDC estimates that two out of every three PCs are infected with spyware.  While a hefty percentage of those devices are probably owned by consumers, spyware is not strictly a consumer problem.  A recent IDC survey of 600 organizations showed that spyware is No. 4 on the list of threats to enterprise network security.

Dell thinks the problem is even more widespread, estimating that 90% of all PCs are infected with spyware.  Calls relating to spyware now make up 20% of all calls to Dell's technical support lines, compared to just 1% to 2% of all calls in August 2003.  It's clear that consumers and companies alike are concerned about software that is intended to log your keystrokes, steal personal or corporate information, enable identity theft, track your online activity, and/or sell such information to anyone willing to pay for it.

Do a Google search on "anti-spyware" and you'll turn up hundreds of links offering just as many products.  The question is, which of those products can be trusted?  In some cases, software that bills itself as anti-spyware is actually PLACING the malevolent code on your PC.  This is one way in which the average PC user can get himself into even more trouble.

Eric Howes, a graduate student at the University of Illinois at Urbana-Champaign has made it a mission to warn computer users about rogue anti-spyware software.  He operates a Web site called The Spyware Warrior.  On this site, Howes lists dozens of software products that "do not provide proven, reliable anti-spyware protection," or that "may use unfair, deceptive, high pressure sales tactics and false positives to scare up sales from gullible, confused users."  Be sure to consult his site at http://www.spywarewarrior.com/ before you buy or install any product.

Linda Musthaler is a principal analyst with Essential Solutions Corporation.