President Obama has ordered a full review of foreign-based digital attacks that U.S. intelligence agencies say were aimed at influencing this year's presidential election, a top White House official said Friday.
The disclosure came after President-elect Donald Trump again dismissed a blunt U.S. intelligence assessment that concluded senior Russian authorities had authorized the digital theft of emails from Democratic Party officials and Hillary Clinton's campaign manager during the campaign.
Trump has repeatedly praised Russian President Vladimir Putin, raising concerns among intelligence experts that he is ignoring potential threats to U.S. national security.
Officials said the cyberattacks were the first known attempt to try to interfere with a U.S. election to discredit American democracy or a specific candidate, a clear escalation of traditional cyberespionage.
The CIA concluded in a secret assessment that Russia directed the hacking to help Trump win the presidency and not just to undermine confidence in the U.S. electoral system, the Washington Post reported Friday.
Intelligence agencies identified individuals connected to the Russian government who participated in the effort to boost Trump and hurt Clinton's campaign, the Post reported.
"We may be crossing into a new threshold and it's incumbent upon us to take stock of that," said Lisa Monaco, White House counter-terrorism and Homeland Security advisor.
U.S. officials will be "very attentive to not disclosing sources and methods that may impede our ability to identify and attribute malicious actors in the future," said Monaco, who disclosed the intelligence review at a breakfast arranged by the Christian Science Monitor.
The classified inquiry will focus on what happened and "lessons learned," Monaco said, and will be completed before Obama leaves office on Jan. 20.
It will be shared with "a range of stakeholders," she said, including members of Congress, but she did not commit to making it public.
Trump has repeatedly derided claims that Russian authorities played a role in the hacks and the subsequent release of thousands of emails from Democratic National Committee staff accounts and the private account of John Podesta, chairman of Clinton's campaign.
In an interview with Time magazine published this week, Trump said he didn't believe Putin's government hacked the Democrats' computers to help his candidacy.
"I don't believe they interfered," Trump said. "That became a laughing point — not a talking point — a laughing point," he said, implying that the intelligence assessments were politically motivated.
The hacking, he said, "could be Russia. It could be China. And it could be some guy in New Jersey."
Trump has rejected a joint statement issued Oct. 7 by Secretary of Homeland Security Jeh Johnson and Director of National Intelligence James R. Clapper, who leads the 17 U.S. intelligence agencies.
The U.S. intelligence community "is confident that the Russian Government directed the recent compromises of e-mails from U.S. persons and institutions, including from U.S. political organizations," the statement said.
"We believe, based on the scope and sensitivity of these efforts, that only Russia's senior-most officials could have authorized these activities," it added.
The statement also said a Russian company apparently had probed computerized voting systems used by individual states, but it stopped short of blaming the Russian government.
Using an emergency communications system set up to prevent an accidental nuclear war, the White House warned Putin's government to stop the cyberattacks and not to interfere with voting systems, according to later reports.
No further disruptions were reported, U.S. officials said. Russia's government has denied any role in the hacks or in trying to subvert the U.S. election.
Several senior Republicans in Congress have broken with Trump on the issue, saying they are convinced by the intelligence.
Sen. John McCain (R-Ariz), chairman of the Senate Armed Services Committee, said "there's very little doubt" that Putin's government sought to interfere with the election.
"The problem with hacking is that if they're able to disrupt elections then it's a national security issue, obviously," he said in an interview.
Sen. Lindsey Graham (R-S.C.) said the Senate Armed Services subcommittee that he heads will investigate Russian hacking when Congress returns next year.
Rep. Devin Nunes (R-Tulare), chairman of the House Intelligence Committee, said that Russian cyberattacks were "no surprise" and that the Obama administration had ignored calls to take more forceful action against Russia.
"The intelligence community has repeatedly failed to anticipate Putin's hostile actions," Nunes said. "It appears, however, that after eight years the administration has suddenly awoken to the threat."
Trump's unwillingness to accept assessments from career intelligence officials is highly unusual. So is his refusal to accept more than a handful of classified intelligence briefings since his upset victory a month ago.
Given Trump's "disturbing refusal to listen to our intelligence community and accept that the hacking was orchestrated by the Kremlin, there is an added urgency ... for a thorough review," said Rep. Adam B. Schiff (D-Burbank), top Democrat on the House Intelligence Committee.
Sen. Dianne Feinstein (D-Calif.), the top Democrat on the Senate intelligence committee, said that she had become increasingly concerned over the last six months about Russian government efforts "to influence our election" and agrees that "only the senior-most government officials in Russia could have ordered this effort."
The German and British governments also raised alarms this week about foreign cyberattacks on their political systems.
German Chancellor Angela Merkel's government published a stark rebuke of Russia on Thursday, accusing Moscow of using hackers to spread fake information to discredit German democracy.
In London, Alex Younger, head of the British Secret Intelligence Service, commonly known as MI6, warned of hostile governments trying to undermine democratic institutions, without naming Russia specifically.
"They do this through means as varied as cyberattacks, propaganda or subversion of democratic process," he said Thursday in a rare public address.
Some of the stolen Democratic emails, which were posted by WikiLeaks and other websites in the heat of the campaign this summer and fall, proved politically damaging to Clinton's campaign.
They fueled accusations that Democratic Party officials had helped Clinton's aides defeat her rival Bernie Sanders in the primaries, and that the Clinton family had benefited financially from the Clinton Foundation global charity.
When Democratic National Committee officials realized their network was hacked last spring, they called CrowdStrike, an Irvine-based cybersecurity firm that tracks global hacking groups.
CrowdStrike revealed in July that two "Russian espionage groups" known as APT 28 and APT 29 — which cyber experts dubbed Fancy Bear and Cozy Bear — had implanted malicious "backdoors" into the DNC networks.
The company said it identified the groups by the way they penetrated the networks and by the telltale computer code they left behind.
"Their tradecraft is superb, operational security second to none and the extensive usage of 'living-off-the-land' techniques enables them to easily bypass many security solutions they encounter," CrowdStrike wrote.
Government officials given classified briefings have largely confirmed the CrowdStrike report.
The two groups were previously linked to hacks of unclassified networks used by the White House, State Department and the Pentagon's Joint Chiefs of Staff, as well as foreign governments.
Times correspondent Lisa Mascaro contributed.
6:35 p.m.: This article has been updated to include new details reported by the Washington Post.
3:20 p.m.: Updated throughout, including new details about the alleged hacking and reaction from members of Congress and foreign governments.