Sources: U.S. did not 'hack back' against North Korea

WASHINGTON -- The U.S. government was not responsible for crippling North Korea's Internet infrastructure after President Barack Obama blamed the country for hacking Sony Pictures Entertainment Inc., two senior U.S. officials said, as Congress announced Friday it will examine North Korea's cyberthreats.

The Obama administration has blamed North Korea for hacking Sony but has been coy about whether it retaliated and caused North Korea's outage, which affected all the nation's Internet connections starting the weekend of Dec. 20. The two officials, speaking on condition of anonymity because they were not authorized to openly discuss the issue, acknowledged it was not a U.S. operation.

In a twist, North Korea has denied it hacked Sony but blamed the U.S. government for causing its Internet outages.

It was not clear even within the administration whether rogue hackers or other governments disrupted North Korea's networks.

North Korea's service was sporadic Dec. 20, then collapsed entirely for nearly 10 hours two days later.

Within the U.S. government, contingents have debated whether to acknowledge the U.S. played no role in North Korea's disruptions or remain silent to avoid conversations about U.S. capabilities and policy on offensive cyberoperations, which are considered classified.

The disclosure denying U.S. involvement was intended to convey how seriously the administration considers cyberattacks, intended to be used only in the most serious cases and consistent with the State Department's admonitions for foreign governments to preserve access to the Internet for all citizens, one of the officials said.

The Republican-led Congress said Friday it will convene a hearing Tuesday about North Korea's cyberthreats with testimony from senior officials at the departments of State, Treasury and Homeland Security.

The U.S. government hinted Jan. 2 it wasn't involved in the North Korea outages, but its intended message was too understated to be recognized as an outright denial.

When the White House announced new economic sanctions against North Korea for what it called a "destructive and coercive cyberattack" against Sony, Obama spokesman Josh Earnest described the sanctions as "the first aspect of our response." In other words, the government was saying its initial response was coming 11 days after the mysterious attacks crippled North Korea's networks.

As late as Thursday, Obama's homeland security adviser, Lisa Monaco, declined to say whether the U.S. was behind the North Korea outages. At a cybersecurity conference in New York, Monaco would not answer a question from the U.S. attorney for the Southern District of New York, Preet Bharara, whether the administration was responsible and agreed it could be helpful to be ambiguous about the consequences of hacking American targets.

"I'm not going to comment, and I never would, on operational capabilities," she said.

At the time of the North Korea outages, the White House and State Department declined to say whether the U.S. was responsible. North Korea's four principal connections to the Internet began having serious problems just hours after Obama blamed North Korea for hacking into Sony and promised to retaliate. The hacking disclosed confidential company emails and business files and included threats of terror attacks against U.S. movie theaters until Sony agreed to cancel the Christmas release of its film "The Interview." Sony eventually decided to release the profane comedy that pokes fun at North Korea leader Kim Jong Un and depicts an assassination plot against him, offering it online for $6 and in a relatively small number of theaters.