The Anthem data breach may have exposed 78.8 million records, according to a more finely tuned estimate by the health insurance company, but Anthem is still investigating exactly how many records hackers extracted from a database.
Hackers accessed a database at Anthem that contained customer and employee records with names, birth dates, Social Security numbers, addresses, phone numbers, email addresses and member IDs, the health insurance company said on Feb. 4. Some records included employment information and income levels, but no financial information was compromised, it said.
It marked one of the largest data breaches to affect the health care industry, adding to a string of recent attacks that have shaken large companies, including retailers Home Depot, Target and Michaels.
Anthem, formerly known as Wellpoint, runs health-care plans under the Blue Cross Blue Shield, Empire Blue Cross, Amerigroup, Caremore, Unicare, Healthlink, DeCare, HealthKeepers and Golden West brands.
Between 60 million and 70 million of the 78.8 million records belong to current or former Anthem members, the company said in a statement.
The remainder -- between 8.8 million and 18.8 million -- belong to non-Anthem members who used their insurance in a state where Anthem has operated over the last decade.
Anthem is still trying to identify those people who may have been affected. Part of the problem is that Anthem has found 14 million incomplete records that can't be linked to a product or line of business. Those records lack data fields that could be used to identify members, though they probably are not active Anthem members.
The incomplete records may have been created by legacy systems, were claims that were received without member information, or came from a third party, Anthem said. However, some do have valid mailing addresses, so Anthem will notify those people.
No information has been formally released on who may have compromised the database. Security firm CrowdStrike, which is not involved in the investigation, said the attackers used infrastructure linked to a suspected China-based state-sponsored group known as Deep Panda.
The intrusion is believed to have occurred over several weeks starting on Dec. 10. Anthem hired Mandiant, the computer forensics unit of FireEye, to investigate the breach, and the FBI is involved.