Roger Stone speaks to the media at Trump Tower on December 6, 2016 in New York City. Spencer Platt/Getty Images President Donald Trump's former campaign adviser and longtime confidant Roger Stone testified before the House Intelligence Committee on Tuesday, six months after admitting that he exchanged private messages with a hacker implicated in a massive cyberattack that targeted the Democratic National Committee last year.

Stone told Business Insider in March that he had a private conversation on Twitter with the person, nicknamed "Guccifer 2.0," and that the interaction was so "brief and banal, I had forgotten it."

"Not exactly 007 stuff even if Gruccifer 2.0 [sic] was working for the Russkies," Stone said. "Meaningless."

In his opening statement to the committee, which was leaked Monday night, Stone cast doubt on the intelligence community's assessment that Guccifer 2.0 was a front for Russian intelligence.

He pointed to a report written by Veteran Intelligence Professionals for Sanity (VIPS), publicized by The Nation in August, claiming that the theft of DNC emails was not a hack, but a leak.

"Now that more information is in the public domain, the very question of whether Guccifer 2.0 hacked the DNC must be revisited in light of the VIPS report cited by The Nation," he said.

After his testimony, Stone told reporters that he believed the DNC hack was an "inside job," pointing again to the report in The Nation.

But the Nation's editor, Katrina Vanden Heuvel, issued a mea culpa following the article's publication, noting that "several of the article's conclusions" were mistakenly presented as "certainties" rather than "possibilities."

"And given the technical complexity of the material, we would have benefited from bringing on an independent expert to conduct a rigorous review of the VIPS technical claims," she wrote.

Roger Stone at the premiere of "Get Me Roger Stone." Mike Coppola/Getty Images for Tribeca Film Festival Guccifer 2.0, who has said that they targeted Democrats in the heat of the election last summer, has denied having any links to Russia. But digital fingerprints were left on the hacks that led the US intelligence community — as well as several private cybersecurity firms — to conclude that the cyberattacks were largely, if not entirely, carried out by two Russian intelligence groups.

Piecing together Guccifer's comments and cyber trails, experts soon began to agree that the self-proclaimed hacker was either a poser or the product of a Russian disinformation campaign. ThreatConnect, a cybersecurity firm based in Arlington, Virginia, concluded that Guccifer 2.0 had been using the Russian-based Virtual Private Network service, Elite VPN, to secure their communications.

For his part, Stone cast aside any suggestion that he may have collaborated with the DNC hackers, Russian or not, telling Business Insider months ago that he first noticed on August 14, 2016— after he'd written an article for Breitbart saying he thought Guccifer was "the real deal" — that a Twitter account that apparently belonged to Guccifer had been reinstated after a brief suspension.

"I wrote an article for Breitbart on August 5, 2016, in which I express my view that Guccifer 2.0 was not a Russian asset," Stone said in his statement for the House Intelligence Committee. "My only exchange with Guccifer 2.0 would begin on August 14, 2016, after my article appeared, and ran through September 9, 2016."

Screenshots of Stone's back-and-forth with Guccifer via Twitter direct messaging were first revealed by The Smoking Gun. Stone later shared them with Business Insider.

"Long after Grufficer's [sic] bit part in this drama, I did in fact have a short and innocuous Direct Message Exchange with Gruccifer 2.0," Stone said. He told The Smoking Gun that he thought the messages had been public.

Business Insider could not independently confirm if Stone's screenshots accurately portrayed the entirety of his conversation with Guccifer. But in what appeared to be the first message in their conversation, Stone said he was “delighted” that Twitter had reinstated Guccifer 2.0’s account.

Stone messaged Guccifer again on August 16 and asked if the alleged hacker could retweet his column about the 2016 presidential election possibly being “rigged.”

“i’m pleased to say that u r great man,” Guccifer 2.0 replied on August 17. “please tell me if i can help u anyhow. it would be a great pleasure to me.”

Paul Manafort, Campaign Manager for Donald Trump, speaks on the phone while touring the floor of the Republican National Convention at the Quicken Loans Arena as final preparations continue July 17, 2016 in Cleveland, Ohio. Win McNamee/Getty Images

Stone's tweets in the days after raised questions about whether he knew in advance that emails from Hillary Clinton's campaign chairman, John Podesta, would be imminently published by WikiLeaks.

"Trust me, it will soon the Podesta's time in the barrel. #CrookedHillary," Stone tweeted on August 21.

Stone said in his statement on Monday that his tweet about Podesta "must be examined in context."

"I posed this at a time that my boyhood friend and colleague, Paul Manafort, had just resigned from the Trump campaign over allegations regarding his business activities in Ukraine," Stone wrote.

"I thought it manifestly unfair that John Podesta not be held to the same standard. Note, that my Tweet of August 21, 2016, makes no mention, whatsoever, of Mr. Podesta's email, but does accurately predict that the Podesta brothers' business activities in Russia ... would come under public scrutiny."

Stone tweeted again on October 1, 2016, however, that “Wednesday @HillaryClinton is done."

"I have total confidence that @wikileaks and my hero Julian Assange will educate the American people soon #LockHerUp," he tweeted two days later.

"Payload coming. #Lockthemup," Stone tweeted on October 5. On October 7, shortly after an Access Hollywood video surfaced of Trump making lewd remarks about women, WikiLeaks published the first batch of Podesta emails.

"I think there’s a reasonable belief that Mr. Assange may have passed this information onto Mr. Stone," Podesta told reporters later.

Stone has denied having any direct contact with WikiLeaks, saying that he had been getting his information from a mutual friend he shared with Assange. He refused to name the intermediary in an interview with Yahoo News published on Monday.

Democratic congressman Mike Quigley said he asked Stone again on Tuesday for the name of the intermediary, but Stone "refused to answer."

"I had no contacts or communications with the Russian State, Russian Intelligence or anyone fronting for them or acting as intermediaries for them," Stone told Business Insider earlier this year. "None. Nada. Zilch. I am not in touch with any Russians. don't have a Russian girlfriend, don't like Russian dressing and have stopped drinking Russian Vodka."

Read Stone's full statement below:

Stone Opening Statement by natasha on Scribd

Bryan Logan contributed reporting.