WASHINGTON — The Justice Department announced charges on Monday against four members of China’s military on suspicion of hacking into Equifax, the credit reporting agency, in 2017 and stealing trade secrets and the personal data of about 145 million Americans.
“This was a deliberate and sweeping intrusion into the private information of the American people,” Attorney General William P. Barr said in a statement ahead of a news conference.
The charges underscored China’s quest to obtain the personal data of Americans — which Beijing can use to propel advances in artificial intelligence and espionage — and its willingness to flout a 2015 agreement with the United States to refrain from hacking and cyberattacks, all in an effort to expand economic power and influence.
Though not as large as other major breaches, the attack on Equifax was far more severe. Hackers stole names, birth dates and Social Security numbers of millions of Americans — data that can be used to access information like medical histories and bank accounts.
The attack on Atlanta-based Equifax “is of a piece with other Chinese illegal acquisitions of sensitive personal data,” Mr. Barr said, citing China’s theft of records in recent years from the government’s Office of Personnel Management, Marriott International and the insurance company Anthem.
“This data has economic value, and these thefts can feed China’s development of artificial intelligence tools,” Mr. Barr said in announcing the charges on Monday at the Justice Department. He also said that Beijing can use caches of personal information to better target American intelligence officers.
Law enforcement officials have not yet found evidence that the Chinese government has used the data from the Equifax hacking, David Bowdich, the deputy director of the F.B.I., said at the news conference.
The charges against members of the Chinese military were unusual, Mr. Barr said. The Justice Department rarely secures indictments against members of foreign militaries or intelligence services, in part to avoid retaliation against American troops and spies, but Mr. Barr said it has made exceptions for state-sponsored actors who hacked into American networks to steal intellectual property or interfere in United States elections.
The “deliberate, indiscriminate theft of vast amounts of sensitive personal data” from Equifax cannot be countenanced, Mr. Barr said.
The nine-count indictment accused the Chinese military of hacking into the company’s computer networks, maintaining unauthorized access to them and stealing sensitive, personally identifiable information about Americans.
China has “pioneered an expansive approach to stealing innovation,” Christopher A. Wray, the director of the F.B.I., said Friday at a conference on the threats posed by China.
Mr. Wray said that China is racing to obtain information about sectors as diverse as agriculture and medicine to advance its economy, using a mix of legal means like company acquisitions and illicit acts like spying and cyberattacks.
“They’ve shown that they’re willing to steal their way up the economic ladder at our expense,” Mr. Wray said.
In the months after Equifax was hacked, security researchers found that criminals had siphoned information over a few months after gaining access to the network. But at that time, the attack was not thought to be a state-sponsored hacking.