CareFirst, a BlueCross BlueShield plan, on Wednesday became the third major health insurer in the United States to disclose this year that hackers had breached its computer systems and potentially compromised some customer information.
The attack could affect as many as 1.1 million of its customers. But CareFirst said that although the hackers gained access to customer names, email addresses and birthdates, they did not obtain sensitive financial or medical information like Social Security numbers, credit card information and medical claims.
The company, which has headquarters in Maryland and serves the Washington area, said the attack occurred in June and described it as “sophisticated.”
Chet Burrell, CareFirst’s chief executive, said the company contacted the FBI, which is investigating attacks against the insurers Anthem and Premera. “They are looking into it,” he said.