Michael Riley and Jordan Robertson write the data breach compromised Social Security numbers, birthdates and email addresses of 80 million Anthem customers.
Investigators found technical details and other pieces of evidence that point to a nation-state as the source of the attack, according to the report.
The data breach affected customers that include Michael Daniel, President Barack Obamaâs chief adviser on cybersecurity, and employees of Northrop Grumman and Boeing, Bloomberg reports.
Adam Meyers, vice president of intelligence at cybersecurity firm Crowdstrike, told Bloomberg the attack follows the pattern of a hacking group dubbed “Deep Panda.”
The hacking unit has been targeting defense contractors and healthcare providers over the past several months, according to the report.