A rogue computer program that steals electronic documents and covers its own tracks has invaded dozens of computers in a nationwide computer network, a published report said. The program has infiltrated the computers of corporations, non-classified military installations, government laboratories and several universities, The New York Times reported in today's editions. Los Alamos National Laboratory, Digital Equipment Corporation, Harvard University, Boston University and the University of Texas are among the affected institutions, unidentified investigators told the Times. The computer network is Internet, a worldwide collection of computer systems that links corporations, government projects and universities together. Government computer security teams have been unable to trace the source of the illegal program. Their job has been especially difficult because the program automatically erases computer files that would help them trace break-ins, the newspaper said. No classified military computers have been affected and damage has been slight to the Internet system, unidentified government officials told the newspaper. The computer attack is being run through a single hidden location. But in order to avoid detection, the hacker is connecting to Internet through a series of computers. The program is designed to find a file containing the system's passwords and copy the file into another computer for decoding. Some of the break-ins were traced to Texas and New Mexico before investigators lost the trail. Internet was thrown into chaos in November 1988 when a program written by Robert Tappan Morris, a graduate student at Cornell University, jammed the system. The new program is not the same as one that Morris used. That program, called a worm, copied itself from computer to computer, as a computer virus does. ``The computer virus frenzy is not the real problem,'' said Peter Neumann, a computer security expert at SRI International, a research center in Menlo Park, Calif. ``The real problem is the fact that the computers are so vulnerable, and whether the attack is by one person at a computer or a program like a worm or virus, they're all exploiting the same problem _ the vulnerability of our computer systems.''