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MIT computer centers combat several viruses

By Mauricio Roman

Almost every MIT laboratory that uses Macintosh computers is infected with viruses, according to Andrew Bennett, a supercomputer consultant at MIT Information Services. Most recently, viruses were found in the MicroComputer Center, the Condensed Matter Physics Laboratory, and the Laboratory for Architecture and Planning.

A virus is the most common type of pest that affects computers. Viruses need programs in order to cause damage. When a program is run in an infected computer, the virus can install itself in that program. It can then cause irreparable damage, such as erasing files -- including its host. The virus is transmitted when the infected program is run in other computers.

The types of viruses that have been found at MIT so far are not deliberately destructive, Bennett said. These types include the viruses "nVIR A," "nVIR B," and "scores" -- so called because those words appear in printouts of infected programs. These viruses cause the computer to slow down, as well as crash randomly, and give read/write errors and print errors. Specifically, the scores virus damages the system software, and nVIR damages specific programs. However, truly destructive viruses, such as one that wipes the boot blocks of hard disks, could infect Macintosh computers at MIT in the near future, Bennett asserted.

The best way to combat viruses is to practice preventive health care with computers, Bennett said. This could be accomplished by installing vaccines in every Macintosh computer at MIT, he explained. Vaccines are programs that prevent most viruses, including scores, from entering programs run in infected machines. However, vaccines do not detect viruses already present in programs that one copies to a Macintosh, and thus do not prevent machines from getting infected by such programs.

A new program called "Disinfectant" detects and removes viruses from machines. A good preventive measure is to run this program periodically in every computer in a lab, according to Bennett. The MicroComputer Center, for example, disinfects its machines every day, "but labs that are less exposed could do it every month," he said. Both vaccines and Disinfectant are available free of cost at the Microcomputer Center at MIT, Bennett added.

Two other common computer plagues are worms and Trojan horses. Worms do not need programs to propagate for they are programs in themselves. They propagate through networks, as was the case last November when a worm -- mistakenly labeled a virus in the national press -- propagated through Arpanet and caused severe damage at MIT and in labs throughout the United States.

Trojan horses appear to be real programs, but they actually are destructive agents. When they are run they can delete all of one's files.

Neither worms nor Trojan horses have been found in Macintosh computers at MIT so far, according to Bennett. "In fact," he said, "worms that propagate through AppleTalk [the communications network for Macintosh computers] do not exist -- yet."