The viruses, detected a few days after Thanksgiving and linked to criminal networks in Russia, China and other countries, may have been at work for years, the San Francisco Chronicle reported Friday.
The viruses were discovered when the college's data security monitoring service detected an unusual pattern of computer traffic, school officials said.
David Hotchkiss, the school's chief technology officer, said his security team found at least seven viruses trolling the college networks and transmitting data to sites in Russia, China and at least eight other countries, including Iran -- and the United States.
Computers have been infected across the college district's administrative, instructional and wireless networks, he said, and it's likely personal computers belonging to anyone who used a flash drive on campus during the past decade to carry information home were also affected.
While some of the stolen data is probably innocuous, an analysis found students and faculty have used college computers to do their banking and the viruses have captured the information, Hotchkiss said.
"We may never know the full extent of the damage, and how many lives have been affected by this," Hotchkiss told three college trustees Thursday evening. "These viruses are shining a light on years of (security) neglect."
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