More than 300,000 personal records for faculty, staff and students who have received identification cards at the University of Maryland were compromised in a cybersecurity breach this week, according to school officials.

At around 4 a.m. on Tuesday, an outside source gained access to a secure records database holding information dating back to 1998. The VP and CIO of U-Md., Brian Voss, says officials think that whoever got into the database duplicated the information, which includes names, Social Security numbers, birthdates and university identification numbers. Essentially, he said, the attackers “made a Xerox of it and took off,” The Washington Post reports.

Voss stated concern that the attacker or attackers must have had a very significant understanding of how the school’s data was designed and protected.

U-Md. plans to provide free credit monitoring for a year to anyone whose information was compromised.