Anthem's breach exposed 78.8M health records — the largest healthcare data theft

In February 2015, Anthem Inc., one of the largest health insurance companies in the US, disclosed that hackers had accessed its database and stolen approximately 78.8 million customer records. The stolen data included names, Social Security numbers, medical IDs, addresses, dates of birth and income information.

The breach was attributed to a state-sponsored hacking group (believed to be Chinese). The hackers gained access through a phishing email that compromised an employee's credentials, then moved laterally through Anthem's network to the database.

Anthem paid $115 million in a class-action settlement — the largest data breach settlement in history at the time. The case illustrated how healthcare data is uniquely valuable to hackers (it cannot be changed like a credit card number) and how a single phishing email can compromise the most sensitive personal data of tens of millions of people.