WASHINGTON (AFP) -- A secret CIA assessment has found that Russia sought to tip last month's US presidential election in Donald Trump's favor, The Washington Post reported Friday, a conclusion that drew an extraordinary rebuke from the president-elect's camp.

"These are the same people that said Saddam Hussein had weapons of mass destruction," Trump's transition team said, launching a broadside against the spy agency.

"The election ended a long time ago in one of the biggest Electoral College victories in history. It's now time to move on and 'Make America Great Again.'"

The Washington Post report comes after President Barack Obama ordered a review of all cyberattacks that took place during the 2016 election cycle, amid growing calls from Congress for more information on the extent of Russian interference in the campaign.

The newspaper cited officials briefed on the matter as saying that individuals with connections to Moscow provided anti-secrecy website WikiLeaks with emails hacked from the Democratic National Committee, Democratic nominee Hillary Clinton's campaign chief and others. 

Those emails were steadily leaked out via WikiLeaks in the months before the election, damaging Clinton's White House run.

The Russians' aim was to help Donald Trump win and not just undermine the US electoral process, the paper reported.

"It is the assessment of the intelligence community that Russia's goal here was to favor one candidate over the other, to help Trump get elected," the newspaper quoted a senior US official briefed on an intelligence presentation last week to key senators as saying. "That's the consensus view."

CIA agents told the lawmakers it was "quite clear" that electing Trump was Russia's goal, according to officials who spoke to the Post, citing growing evidence from multiple sources.   

However, some questions remain unanswered and the CIA's assessment fell short of a formal US assessment produced by all 17 intelligence agencies, the newspaper said. 

For example, intelligence agents don't have proof that Russian officials directed the identified individuals to supply WikiLeaks with the hacked Democratic emails.

WikiLeaks founder Julian Assange has denied links with Russia's government.

Those individuals were "one step" removed from the Russian government, which is consistent with past practices by Moscow to use "middlemen" in sensitive intelligence operations to preserve plausible deniability, the report said.

At the White House, Deputy Press Secretary Eric Schultz said Obama called for the cyberattacks review earlier this week to ensure "the integrity of our elections."

"This report will dig into this pattern of malicious cyberactivity timed to our elections, take stock of our defensive capabilities and capture lessons learned to make sure that we brief members of Congress and stakeholders as appropriate," Schultz said.

Obama wants the report completed before his term ends on January 20.

"We are going to make public as much as we can," the spokesman added. "This is a major priority for the president."

The move comes after Democrats in Congress pressed the White House to reveal details, to Congress or to the public, of Russian hacking and disinformation in the election.

On October 7, one month before the election, the Department of Homeland Security and the Director of National Intelligence announced that "the Russian Government directed the recent compromises of emails from US persons and institutions, including from US political organizations."

"These thefts and disclosures are intended to interfere with the US election process," they said.

Trump dismissed those findings in an interview published Wednesday by Time magazine for its "Person of the Year" award. Asked if the intelligence was politicized, Trump answered: "I think so."

"I don't believe they interfered," he said. "It could be Russia. And it could be China. And it could be some guy in his home in New Jersey."

Worried that Trump will sweep the issue under the rug after his inauguration, seven Democrats on the Senate Intelligence Committee called on November 29 for the White House to declassify what it knows about Russian interference.

The seven have already been briefed on the classified details, suggesting they believe there is more information the public should know.

On Tuesday this week, leading House Democrats called on Obama to give members of the entire Congress a classified briefing on Russian interference, from hacking to the spreading of fake news stories to mislead US voters.

Republicans in Congress have also promised hearings into Russian activities once the new administration comes in.  

Obama's homeland security advisor Lisa Monaco said the cyber interference goes back to the 2008 presidential race, with both the Obama and John McCain campaigns hit by malicious computer intrusions.

Russian hacking and election interference have also become a big issue in Germany.

On Thursday, Germany's domestic intelligence agency BfV issued a stark warning over a rising Moscow-directed campaign of hacking and misinformation directed at "destabilizing" the country and influencing political discourse.

Last week, WikiLeaks published stolen documents on intelligence activities that embarrassed Chancellor Angela Merkel just as she began campaigning for elections slated for late 2017.