Speaking at a news conference broadcast on Periscope Monday, the founder and editor-in-chief of WikiLeaks said the report was "embarrassing to the reputation of the US intelligence services."
A report from US intelligence officials Friday assessed
"with high confidence" the GRU Russian intelligence agency "used the Guccifer 2.0 persona, DCLeaks.com, and WikiLeaks to release US victim data obtained in cyberoperations publicly."
The intelligence community also assessed "with high confidence" that the GRU provided WikiLeaks with the material it obtained from hacking the Democratic National Committee and top Democratic officials.
Assange calls report a "press release"
Assange hit back by labeling the report a "press release" and criticized the Obama administration for politicizing the US intelligence services.
"Most of this so-called intelligence report is not even fabricated," he said, suggesting there wasn't enough in it to be made up.
"It does not even make assertions for the most part... it uses speculative terms... it engages us in sneaky conflations... How good a report is it as an intelligence report from 1 to 10? The evidentiary weight is literally zero. There is no evidence of any kind supplied," Assange said.
Assange spoke from the Ecuadorian Embassy in London, where he's been holed up for more than four years to avoid facing sexual assault charges in Sweden and a potential extradition to the United States.
He gave little away when asked by CNN whether WikiLeaks acted as a go-between as suggested by the report.
"We can't play 20 questions to our sources. Each piece of information you disclose about the source narrows the scope of any investigation... if our sources were, for example, a state, we would have a lot less concern in attempting to protect them."
The report was the first official, full and public accounting by the US intelligence community of its assessment of Russian cyberhacking activities during the 2016 presidential campaign and election, and the motivations behind that hacking.
On Monday, Kremlin spokesman Dmitry Peskov told journalists in a conference call that the charges against Russia "were not backed by anything" and were "made on a very amateur, emotional level."
"What we see is ... that all of this looks like is a full-scale witch hunt."