WASHINGTON (Reuters) - A federal grand jury charged a Chinese national in a 2015 hacking campaign that affected large U.S. businesses including insurer Anthem Inc, where the breach affected a computer system containing data on nearly 80 million people, according to an indictment unsealed on Thursday.

Fujie Wang, 32, and others including one individual charged as John Doe, conducted intrusions into Anthem and three other American businesses, according to the four-count indictment in federal court in Indianapolis, where Anthem is based. It did not identify the other companies by name.

The hackers used sophisticated techniques to hack into the businesses’ computer systems and installed malware, then identified information of interest including personally identifiable information (PII) and business information.

“The allegations in the indictment unsealed today outline the activities of a brazen China-based computer hacking group that committed one of the worst data breaches in history,” said U.S. Assistant Attorney General Brian Benczkowski.

Wang and Doe were charged with conspiracy to commit fraud in relation to computers and identity theft, conspiracy to commit wire fraud, and intentional damage to a protected computer, the Justice Department said.

The “extremely sophisticated hacking group” ultimately stole data concerning nearly 80 million people from Anthem’s computer networks, the Justice Department said in a statement.

The information accessed included names, birthdays, Social Security numbers, street addresses, email addresses and employment information, including income data, it said.

In July 2017, Anthem agreed to settle litigation over the breach for $115 million, which lawyers said would be the largest settlement ever for a data breach.