Viruses, worms, and other nasties: practicing safe computing

TechTalk
By Ken Doyle

Over the past few months, I’ve been constantly reminded how lucky I am for depending on Macintosh computers to do most of my work. These reminders, called “Windows Updates,” have been popping up with alarming frequency when I boot up my PC running Windows XP.

According to the WildList (www.wildlist.org), there are currently 619 known viruses that infect Windows PCs, and 5 that affect other operating systems. No viruses presently exist for Mac OS X, the operating system on Apple Macintosh computers.

The term “virus” is often used generically to describe any malicious program. In reality, there are three types of problems that Windows users most commonly encounter—viruses, worms, and Trojan horses.
A true virus is a program that must be able to execute itself without the user’s intervention. Typically, a virus does this by infecting another, “host” program. A virus must also be able to replicate—that is, make copies of itself.

A worm is a program that does not require a host but is able to replicate and spread across computer networks.

A Trojan horse is a malicious program that appears to be something innocent, such as a screensaver. Trojan horses cannot execute themselves—you have to run them, most commonly by opening an e-mail attachment. Once a Trojan horse runs, it can destroy files or create “holes” in your system that can be accessed by hackers.

When it comes to dealing with security threats, preventive maintenance goes a long way. First, make sure you keep up with the constant stream of security patches issued by Microsoft through the Windows Update program.

Second, use an antivirus program; in fact, don’t even think about running Windows without one. Keep your antivirus subscription active and regularly check for updates.

Third, ditch Internet Explorer and Outlook (or Outlook Express). These programs ranked fourth and eighth, respectively, on a list of the top 20 vulnerabilities in Windows, according to the SANS Group (isc.sans.org/top20.html). There are good, alternative browsers and e-mail programs out there—search any popular software archive, such as Tucows (www.tucows.com).

Finally, if you have a broadband Internet connection (such as cable or DSL), install a firewall. If you have a network with multiple PCs, a hardware firewall is most likely built into your router, but you need to configure it correctly for maximum effectiveness. You can also install software firewalls on individual computers.

If all this seems to be a lot of bother, well, it is! Computer professionals around the world are growing increasingly frustrated with Windows and the ongoing security issues. In an ideal world, no single operating system would have a monopoly, and the market would be split among two or three systems. Unfortunately, the world is far from ideal in this respect, and Microsoft’s dominance is likely to continue for a long while.

That said, there are indeed alternatives to the world of Windows, and I’ll examine them in a future column. Meanwhile, keep your PCs protected, and you can minimize the risk.