Hackers have broken into patients' information at the UCLA Health System, exposing the personal and medical history of some 4.5 million people, authorities announced late Friday on its website.
The data breach on the California university's hospital has put patients information at risk, The Los Angeles Times reported.
The UCLA hospital administration could not disclose yet what information in particular had been stolen, but a page devoted to the incident had listed the possibilities, including name and Social Security numbers, medical records, ID numbers and addresses, among others that are usually part of a patient's record when diagnosed.
The problem with the hack is that the patients' information data were not encrypted.
Hospital president James Atkinson told The L.A. Times that UCLA has a speculation that the group responsible for the breach could be from another country and is a "very sophisticated group of hackers."
UCLA Health had spotted the suspicious activity on a computer server in October and confirmed a network breach on May 5.
The hospital has begun the process of notifying those who may be affected. UCLA Health is offering a year of free credit monitoring for those whose social security number or Medicare ID number have been compromised and a year of identity theft recovery services to affected individuals as well, according to Fortune.
UCLA Health is now working closely with the Federal Bureau of Investigation and an unnamed forensics company to investigate the attack. It also set up a cybersecurity review team led by UC president and former Secretary of Homeland Security Janet Napolitano.
