By Richard A. Serrano, Tribune Washington Bureau (TNS)

WASHINGTON — The cyberattack on the federal Office of Personnel Management was orchestrated by someone working directly for a foreign government or with a foreign state, a key member of the House Intelligence Committee said Sunday.

“There are only two possibilities here with an attack this sophisticated,” said Rep. Adam Schiff of California, the top Democrat on the panel. “Either a state actor or a group of private hackers who often work in concert with the state.”

But Schiff, speaking on Fox News Sunday, cautioned that the U.S. is not quite ready to say affirmatively who was to blame for one of the worst breaches of federal workers’ personal information.

The data breached in the OPM attack included Social Security information and other personal data belonging to about 4 million federal employees in the U.S. The information also included security clearances for federal employees.

Sources have said the information most likely was acquired to help the perpetrators identify which federal employees might be vulnerable and willing to spy against the United States.

“It’s very valuable information,” Schiff said of the stolen material. “And while we’re not allowed to comment on the attribution yet, we’ve gotten very good at attribution.”

On CNN on Saturday, Schiff strongly suggested that China, as most law enforcement sources have said, or Russia was behind the breach.

“We certainly have made great progress with the investigation,” he said. “I can tell you, as a general matter, that China is a very bad actor in the cyber field, and so is Russia. They not only have state actors, but they have private groups that work in concert with the state and are responsible for all kinds of hacks and theft.”

The U.S. government has yet to identify who was behind the attack that was first detected in April and announced last week. It was the third major intrusion into a major U.S. government computer system in the past year.

On the Republican side, Rep. Michael McCaul of Texas, chairman of the House Homeland Security Committee, agreed with Schiff that China is a top suspect in the intrusion.

“All threat indicators point to the fact that it was China, perhaps nation-state sponsored, because of the way it was done,” he said Sunday on CBS’s Face The Nation. “It was done to get personal information on political appointees and federal employees to exploit them, so later down the road they can use those for espionage.”

McCaul added, “This is an area where there are no rules of the game in terms of espionage and in terms of stealing this kind of information. I think this raises all sorts of issues with Americans.”

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