07/22/96 OUT, OUT, DAMNED VIRUS

OUT, OUT, DAMNED VIRUS
Some are benign, others can wipe out a hard disk. These programs can help
In early June, Microsoft sent 150 journalists copies of a CD-ROM demonstrating a couple of dozen programs designed by other companies to work with Microsoft Office. But the distribution was followed almost immediately by a frantic E-mail message from Microsoft's public-relations agency: Don't use the disk. It's infected with a virus. A replacement is on the way.
It just goes to show that your computer can pick up a virus just about anywhere, including from what would seem to be the most respectable sources. And the risk is getting worse. More and more software is being downloaded from the Internet. And new technologies, such as Sun Microsystems' Java and Microsoft's ActiveX, may open new channels of infection.
LEECHLIKE. Just what is a virus? Strictly speaking, it is any piece of computer code that can spread from machine to machine by attaching itself to programs. Some viruses just cause inane messages, such as ``Happy Birthday Joshi,'' to appear on your display. Some slow down your computer or cause minor glitches. The worst can wipe out all the contents on your hard disk.
Fortunately, protecting yourself is relatively simple. A number of antiviral products on the market will do a fine job of keeping your computer clean. I would recommend sticking with a product that's certified by the National Computer Security Assn. An up-to-date list is available on the World Wide Web at http://www.ncsa.com. A few choices include the Norton Anti-Virus for PCs and Symantec Anti-Virus for Macintosh from Symantec, VirusScan from McAfee Associates, Dr Solomon's Anti-Virus Toolkit from S&S International, and F-PROT Professional from Command Software Systems. The prices range from $45 to $70.
All of these work in more or less the same way. When installed and at regular intervals thereafter, they scan your disk drives looking for the ``signatures,'' characteristic strings of 1s and 0s, left by hundreds of known viruses. Between scans, they monitor every program you run, looking for suspicious behavior, such as attempts to write to areas of your disks that contain system information. The programs differ mainly in how easy manufacturers have made it to install, set options, and update their database of virus information. Ease of use and a free update policy made Norton Anti-Virus my narrow favorite among Windows 95 products. I'm happy with the Symantec Anti-Virus I run on my Mac.
NET THREATS. Your need for good virus protection is likely to increase. For example, the virus that Microsoft accidentally sent out is a new type called a macro virus. These attach to documents, rather than programs, and could infect any machine running Microsoft Word, regardless of the operating system. The species Microsoft accidentally distributed made harmless changes in Word screens, but a more virulent strain keeps the program from saving files. Microsoft recommends general antivirus protection. But software to defend specifically against Word macro viruses is available at http://www.microsoft.com /msword/.
The Internet also creates new threats. Java and ActiveX work by invisibly downloading and running files on your computer, presenting an opportunity for infection every time you surf the Web. While various security measures have been designed into the systems, the bad guys are bound to find ploys that today's defenses don't address.
In all the years that I've been using computers, my machines have been infected by viruses, but I've never suffered a serious loss. I've been lucky, but I've also been vigilant. And I don't intend to relax now.
BY STEPHEN H. WILDSTROM