The Scourage of Computer Viruses
"TIME bombs," "Trojan horses," and "viruses" are man-made bugs that afflict computers and give nightmares to the people who run them. They can choke networks with deadend tasks, spew out false information, erase files, and even destroy equipment.
For the most part, these infestation have been confined to the world of computer hackers and electronic security squads. But occasionally, and with disturbing frequency in he last few months, they have escaped to the world at large and wreaked havoc.
Since November, there have been several outbreaks of black programs. As a result, people who have been warned about them for years are being heeded more closely now and computer operators are becoming more cautious about how they exchange data. One of the strengths of America's computer culture is that is provides a wide-open market for information and ideas. The longterm threat of the bugs is that they may force users to create islands of clean data and erect barriers around them. This spring the electronic marketplace has been flooded with a score of "vaccines" and "inoculation programs" designed to tag infestations and quarantine them.
A computer virus, according to Fred Cohen of the University of Cincinnati, is a program that infects other programs by modifying them to include a version of itself. Like real viruses, these ones carry a genetic code, recorded in this case in machine language. The code tells a "host" system to insert the virus into its main logic, usually on a hard disk. Once established, the virus silently infects every other program it can reach. For example, a floppy disk that is formatted in an infected computer will itself be infected and may carry the virus to other hosts.
Viruses are often created by vandals. But they have also been released accidentally by security experts trying to fight vandalism and by curious programmers who were engaged in experiments. Once hatched, the viruses seem to take on a life of their own.
The first viruses, according to Philip McKinney of ThumbScan, Inc., a computer security firm in Oakbrook, Illinois, were developed by software companies in the 1970s for a legitimate purpose. They are used to trace the evolution of programs that were being copied illegally. These little bugs never showed their presence; they just kept track of their parentage. Authors who knew how to read them hoped they could be used to traced the routes of piracy.
Along with its genetic code, a computer virus may carry a benign or malicious agent. A benign agent, for example, might send a message flashing accross the host's video screen. In in-house games played by one software writer against another, they may simply announce, "Gotcha!c or challenge the person at the terminal to an unwanted logical joust. A malicious agent might order the host to kill every file within reach. Usually the self-destruct command is delayed for a period during which the virus replicates, allowing for wider dispersal. The most destructive agent so far, McKinney...
This is a preview. Get the full text through your school or public library.