Feb 5, 2015 · 1 minute

Anthem has suffered a data breach which could have made the names, social security numbers, addresses, and birthdays of "tens of millions" of people available to hackers.

The affected database is said to store information about 80 million of the company's employees and customers. Anthem is the second-largest health insurer in the country.

According to the Wall Street Journal, the breach was discovered in the middle of last week, which is earlier than most hacks affecting large companies are ever detected.

The company claims the breach was the result of a "very sophisticated external cyber attack" of which the FBI was immediately made aware when it was first discovered.

Yet these attacks aren't often "sophisticated." The data breach at JPMorgan Chase was caused by an oversight. Target ignored multiple warnings before its infamous breach.

This hack is the largest the health care industry has faced since a breach at Community Health Systems compromised the information of some 4.5 million people in 2014.

Bloomberg reports that hacking health care companies has become more appealing to attackers, however, because they hold large amounts of data about millions of people.

Anthem said in a statement that it will reach out to affected customers to inform them of the breach and offer them free credit-monitoring. It has hired FireEye, the company that investigated the Sony Pictures Entertainment hack, to look into this data breach.

[illustration by Hallie Bateman]