Health insurer Premera Blue Cross said on Tuesday that a major cyberattack on its systems may have exposed the personal or medical data of as many as 11 million people, NBC News reported. The company said that hackers launched a "sophisticated attack" beginning May 4, 2014, and gained "unauthorized access" to the names, Social Security numbers, contact information, bank account numbers and even clinical information from claims. Another Blue Cross insurer, Anthem, said last month that it was hit by a similar attack that may have affected as many as 80 million records.