The massive data breach of almost 80 million records of health care consumers insured by Anthem has been linked to the Chinese, according to a report in the Washington Post.

“The malware is so unique — the digital signature is so precise — in these two incidents that we strongly feel the same Chinese actors were involved,” Rich Barger, chief intelligence officer of cybersecurity firm ThreatConnect, told the newspaper.

The malware used in the attack, the largest known breach to date of data held by an insurer, is a match for software used in 2014’s attack on defense contractor VAE, the newspaper reported.

The attack occurred in early February. Anthem claims no medical or credit card information was compromised, but the hackers did gain access to 78.8 million customer names, birthdays, Social Security numbers, addresses and employment data.

China has denied the attack.