A data breach at health insurer Anthem Inc. has affected up to 80 million people, in a serious case already handled by the FBI. Joseph R. Swedish, president and CEO Anthem, said that his company was the target of "a very sophisticated external cyber attack," and that the attackers gained unauthorized access to Anthem?s IT system and have obtained personal information from the company's current and former members such as their names, birthdays, medical IDs/social security numbers, street addresses, email addresses and employment information, including income data. He added that there is no evidence that credit card or medical information, such as claims, test results or diagnostic codes were targeted or compromised.

Once the attack was discovered, Anthem tried to close the security vulnerability, contacted the FBI and began cooperating with their investigation. Anthem has also retained cybersecurity firm Mandiant to evaluate its systems and identify solutions based on the evolving landscape.

Anthem has started to individually notify current and former members whose information has been accessed.

"Obviously it's quite concerning that we would have yet another intrusion of this size," Michael Daniel, President Barack Obama's cybersecurity adviser said at a seminar organized by Bloomberg Government.

"It's particularly disturbing especially when it hits that many people," Daniel said, advising affected consumers to change their passwords and monitor their credit scores.