An accused computer hacker who infiltrated the computer networks at Harvard, Amherst College, Bowdoin College and several businesses in the United States pleaded guilty last Monday to four federal computer hacking charges.

Sean Trifero, a 21-year-old resident of Middletown, R.I., entered his plea in Boston's Federal District Court. He was originally charged at an earlier hearing, but changed his plea last week.

Trifero, the operator of a web site devoted to hacking and an internet chat line focusing on computer viruses, broke into a Dunster House computer on or around October 10, 1996.

After hacking over a two year period from August 1996 to July 1997, Trifero was charged with "knowingly" causing transmission of programs and computer code "to a computer system owned and operated by Dunster House, Harvard College" for the purpose of causing "damage to a computer" and with holding access to that computer, the official charge stated.

According to a court report read at the change of plea hearing by U.S. Attorney Donald K. Stern, the computer was shut down for two weeks in order to repair the damage caused by the hacker.

Trifero caused approximately $27,000 in damages at Harvard.

A self-taught computer hacker with formal education limited to some work at community colleges in Rhode Island, Trifero allegedly began his illegal activities through the on-line service bbsnet.com.

According to Stern's report, Trifero broke into the Amherst College computer network on or around August 22, 1996. Amherst alerted bbsnet.com of Trifero's activities and the service cancelled his account.

One week later, Trifero signed up for a new account with the service under an assumed name. However Trifero provided bbsnet.com with the same address he used for his cancelled account.

Trifero then used his new account to hack into the computer in Dunster.

From there, he planted an internet relay chat (IRC) program called "eggdrop" which allowed him to illegally transfer files to his computer.

According to the court report, Brad N. Karp, a tutor in Dunster, noticed Trifero on the Dunster system, and notified bbsnet.com, which was able to trace Trifero's path through the computer network.

"IRC is a common way for hackers to break into systems," said Rick Osterberg '96, coordinator of Residential Computing Support.

Despite this intrusion, which took Karp approximately 200 hours over a period of two weeks to repair, Faculty of Arts and Sciences (FAS) Computer Services was not notified of the incident.

"FAS Computer Services prefer to be notified about security incidents that occur on the FAS network," Osterberg said.