Showdown at Trump Tower as President-Elect Set to Receive Intel Briefing The briefing will make clear that the Russians were behind the hacks.

 -- The man who has spent months dismissing concerns over Russia’s electoral hacking and disparaging U.S. intelligence is likely to receive information that he doesn’t want to hear today.

Donald Trump will meet with the director of national intelligence and the heads of the FBI and CIA in his New York skyscraper to receive a highly classified report into Russia’s hacking of U.S. political institutions.

Overnight — just hours after President Barack Obama received the report — new details emerged of just what is contained in the secret document.

A senior official briefed on the intelligence sources, methods and assessments in the report that Trump will receive this morning told ABC News that the findings are clear: The evidence points directly to the Kremlin and to Russian President Vladimir Putin in what one official described as “multiple streams and types of intelligence collection, not just forensic examinations of the hacked systems.”

Those various streams of information gathered by U.S. spy agencies include signals intelligence such as intercepts of communications between Russian officials in which they implicated the Kremlin’s espionage, as ABC News reported last month.

The Washington Post reported late on Thursday that the eavesdropping caught senior Russian officials actually cheering Trump’s surprise victory in November as a success of the Kremlin’s intelligence program.

And Vice President Joe Biden, who was privy to the classified briefing that Trump will receive today, told “PBS NewsHour,” “There’s overwhelming consensus in the community and overwhelming evidence supplied by the community that Russia did engage in an effort to impact on the elections.”

“There is clear evidence that they, in fact, were engaged in activities designed to try and impact in the outcome of the election,” he said, adding that there was “no evidence that they actually tampered with voting booths or tampered with voting rolls.”

Referring to parts of the report that will be made public next week, Biden said, “It will state clearly that the Russians did as a matter of policy” attempt to “discredit the U.S. electoral process” and “attempt to hurt [Hillary] Clinton.”

And on Trump’s and others’ skepticism that the Russians were behind the hacks, Biden said, “The idea that the Russians were not involved in an effort to engage in our electoral process is simply not able to be sustained. They were.”

Biden’s comments came just hours after Director of National Intelligence James Clapper made similar remarks in front of a Senate panel.

Sen. Lindsey Graham, R-S.C., asked Clapper whether he thought the malicious cyberactivity “was approved at the highest level of government in Russia.” Clapper responded, “That’s what we said.”

When Graham pressed, asking who exactly he was referring to, Clapper was clear, saying, “The highest is President Putin.”

The top spy chief also detailed how the international Russian propaganda arm — RT television — was behind a spate of fake and misleading news reports throughout the campaign.

“This was actually part of a multifaceted campaign that the Russians mounted. And of course, RT, which is heavily supported by, funded by ... the Russian government, was very, very active in promoting a particular line, point of view, disparaging our system,” Clapper said.

The assertions directly challenge the incoming president’s oft-stated defense of the Russians and scorn for the U.S. intelligence community.

Trump’s defiant stance continued late Thursday as he again tweeted criticism of U.S. intelligence, saying leaks about the classified report amounted to “politics!”

His latest barrage aimed at America’s spy shops began earlier this week, when he tweeted, “The ‘Intelligence’ briefing on so-called ‘Russian hacking’ was delayed until Friday, perhaps more time needed to build a case. Very strange!”

(There was no delay, according to U.S. officials; the briefing was always scheduled for Friday.)

The Trump Tower showdown may get even more intense since the lead briefer for Trump will be Clapper, who will come face to face with the man he once sacked for what officials say was mismanagement of the Defense Intelligence Agency, retired Army Lt. Gen. Mike Flynn, now Trump’s designated national security adviser.

In his briefing today, officials said, Trump will hear about some of the key Russian players who have been sanctioned by the U.S., including the head of military intelligence, known as the GRU; two known Russian hackers long wanted by the FBI; and a cybersecurity firm in Russia run by Alisa Shevchenko — seen on a video obtained by ABC News leading a seminar about how to break into private computer systems using social engineering, which preys on unsuspecting individuals who are tricked into giving up their log-on credentials and passwords.

Shevchenko spoke with ABC News via encrypted email in the early hours Friday, writing that “my company is not remotely relevant to any things US hacking” and claiming that her “company was deliberately framed” and “there is a number of parties that would largely benefit from it.”

She added that her “company might be framed by a Russian party” or “might as well be framed by the US gov,” but she believed that “overall, the aim of that framing campaign seems to distract public/media attention of whatever is really going on in the cyber political scene.”

“The sanctions list is total nonsense,” she said, referring to the U.S. government’s retaliatory sanctions announced last week.

The intel briefing will take place in a Trump Tower conference room that has been converted into what intelligence officials call an SCIF, a secure compartmented information facility, which is essentially a spyproof meeting room.

For his part, Obama told a Chicago TV station that he hopes Trump will change his mind.

“My hope is that when the president-elect receives his own briefings and is able to examine the intelligence as his team has put together and they see how professional and effective these agencies are, that some of those current tensions will be reduced,” Obama said.

ABC News’ Rhonda Schwartz and Alex Hosenball contributed to this report.