Premera Blue Cross (“Premera”) announced this week that it has been the target of a sophisticated cybersecurity attack in which the information of approximately 11 million individuals has been compromised. This announcement comes on the heels of the cybersecurity attack against health insurer Anthem, Inc., which affected approximately 80 million individuals.

According to Premera, the information that may have been accessed by hackers could include “your name, address, email address, telephone number, date of birth, Social Security number, member identification number, medical claims information and in some cases bank account information.”

Premera states: “[o]ur investigation has not determined that any information was removed from our systems and there is no evidence to date that any such information has been used inappropriately.”

The attack has been ongoing since May 2014, but Premera only recently discovered the breach on January 29, 2015. Since the discovery, Premera has worked with Mandiant, a well-known cybersecurity firm, to investigate the attack and remove the infection from its systems. Premera is mailing letters to notify the affected individuals and is also offering two years of free credit monitoring and identity theft protection services to anyone affected by this incident.

For more information from Premera about this attack, click here.