Not-So-Good Fellas

Stay up late watching TV some night, and you'll probably come across that classic infomercial for the amazing Ronco rotisserie oven. As enthusiastic audience members repeatedly remind us: "Just set it, and forget it!"

That may work for ovens. But it doesn't work for computer security anymore-if it ever did. There's a whole world of strangers who are literally out to get you, and the uninformed or inattentive usually get got first.

Empirical research and the nature of recent attacks suggest that hackers keep getting smarter. New bugs like MyDoom, Netsky, Phatbot and Witty demonstrate alarming levels of sophistication, reach and persistence, says Frederick Felman, vice president of marketing at Zone Labsin San Francisco. Some seem to be the products of loosely affiliated gangs of expert hackers harnessing the power of peer-to-peer networks and working with organized crime and spammers.

The motivation isn't intellectual stimulation or teen angst, but rather profit. Hackers seem less interested in destroying computers these days than infecting them with files that disable security, broadcast personal information, and create zombie networks to distribute spam and mount large-scale attacks.

Meanwhile, vulnerabilities in widely used Windows products are more common and, if anything, more exploitable than ever. While most of last year's 137,000-plus malware (or malicious software) attacks were easily deflected by Windows updates and commercial security tools, it's an after-the-fact strategy requiring more multimegabyte downloads all the time. It only takes one home PC (or network server) whose caretaker has fallen behind to open a door to your entire network.

On those rare occasions when a new bug does succeed, it usually wreaks more economic havoc than the last big bug. Research firm Computer Economics expects February's MyDoom to make a $4 billion mess before its last variant takes a nap next to golden oldies like Melissa and Sircam. Old bugs don't die; some 60,000 are snoozing, just waiting for a wake-up call from a new master. "Blended" bugs like Phatbot exploit old and new vulnerabilities in relentless, multifront attacks.

The point is that, after almost two decades of patching security leaks with Band-Aids, we're more vulnerable than ever. Yes, you need updated antivirus, firewall and other security products-not just on your office network, but on every home PC and traveling laptop that connects to it. But don't think that Microsoft or your security product provider can protect you. The only real defense is self-defense.

Things You Can Do

Steve Gibson is a longtime industry icon who's been helping visitors to Gibson Research Corp.'s Web sitesecure their PCs for free for years. An independent voice, his site is packed with security know-how and small freeware downloads that will test and harden your computer defenses.

Granted, you probably have neither the time nor the inclination to become a security expert. But it's better to gain some knowledge than to be an unwitting target. Here are three ways you can reduce your vulnerability to recent attacks:

1. Check your doors in Windows. Each PC has more than 65,000 ports onto the Internet. Internet scanners have been knocking on seldom-used ports lately, trying to see if anyone's home. The only thing better than a locked door is a door that's "stealthed" or invisible. Gibson's ShieldsUp! and LeakTest scans can tell whether your firewall is properly hiding you from prying eyes and stopping any Trojans.

2. Unplug unneeded services. In its desire to be everything to everybody, Microsoft added some Windows capabilities that never really caught on but are still available to malware programmers. Gibson's DCOMbobulator, Shoot the Messenger, SocketLock, UnPlug n' Pray and XPdite let you check on those services and turn them off with a mouse click.

3. Unbind some ties. Only your dial-up or broadband modem needs to be directly connected to the Internet's TCP/IP protocol. But Windows usually "binds" all of a network's resources to it, exposing critical information. Gibson's NoShare applet "unbinds" the parts of your wired and wireless network that don't need that direct connection, preventing outsiders from exploiting resources as unlikely as a shared printer. His site will also walk you through this process using the procedures in Windows itself.

New Windows vulnerabilities will continue to be found, and hackers will continue to hack. Defensive strategies that work today may well be undermined by new exploits tomorrow. If you only have the time and patience to check one security resource, Gibson's site should be it. However, The Human Firewallis a complementary site focused on the human aspect of security. It can suggest companywide best practices to reduce human security errors.

Security is a hassle; it can be complicated and time-consuming. But ignorance is no longer bliss. Staying up-to-date on security is just a necessary price you have to pay these days for the productivity that computers bring.

is Entrepreneur's technology editor.