Julian Assange has launched a personal attack on Hillary Clinton, accusing her of lying and displaying a "cold creepiness" after the former US presidential candidate told the ABC the WikiLeaks founder is a "tool of Russian intelligence".

In an exclusive interview with Four Corners, Mrs Clinton alleged Mr Assange colluded with a Russian intelligence operation to disrupt the 2016 US election and damage her candidacy for president.

"Assange has become a kind of nihilistic opportunist who does the bidding of a dictator," she said.

"WikiLeaks is unfortunately now practically a fully owned subsidiary of Russian intelligence."

The Wikileaks founder, who has been living inside the Ecuadorian embassy in London since 2012, hit back this morning, tweeting that Mrs Clinton was "not a credible person".

Tweeting a link to the Four Corners interview, Mr Assange said there was "something wrong" with her.

"It is not just her constant lying. It is not just that she throws off menacing glares and seethes thwarted entitlement," he said. "Something much darker rides along with it. A cold creepiness rarely seen."

'They wanted to hurt me and help Trump'

Speaking to Four Corners, Mrs Clinton said the operation against her was directed by Russian President Vladimir Putin.

"I think that their intention, coming from the very top with Putin, was to hurt me and to help [US President Donald] Trump," she said.

In January, the US intelligence community concluded Mr Putin ordered the influence campaign to discredit Mrs Clinton, and had a "clear preference" for her opponent.

Hillary Clinton won the popular vote, but lost the electoral college to Donald Trump. ( Reuters: Rick Wilking )

"Our intelligence community and other observers of Russia and [Mr] Putin have said he held a grudge against me because, as secretary of state, I stood up against some of his actions, his authoritarianism," Mrs Clinton said.

"But it's much bigger than that. He wants to destabilise democracy, he wants to undermine America, he wants to go after the Atlantic alliance and we consider Australia an extension of that."

WikiLeaks received thousands of hacked emails from accounts connected to the Democratic campaign, allegedly stolen by Russian operatives.

The site released the emails over a four-month period in the lead-up to the election in 2016.

Mr Assange has denied the emails came from the Russian Government or any other "state parties".

No doubt WikiLeaks releases timed to aid Trump: Clinton

Mrs Clinton contends the combination of WikiLeaks and the Russian operation contributed to her loss in a tight race.

"There was a concerted operation between WikiLeaks and Russia and most likely people in the United States to ... weaponise that information, to make up stories, outlandish, often terrible stories that had no basis in fact ... which were used to denigrate me, my campaign, people who supported me, and to help Trump," she said.

Vladimir Putin had a "clear preference" for Donald Trump. ( AP: Evan Vucci )

"I lost the electoral college by about 77,000, and what we're finding out is that there had to be some very sophisticated help provided to WikiLeaks ... to know how to target both their messages of suppression and their negative messages to affect voters."

Mrs Clinton pointed to examples of releases by WikiLeaks timed to do her maximum damage or distract from Mr Trump's campaign scandals.

At 4:00pm on October 7, The Washington Post published the 2005 Access Hollywood recording of Donald Trump's lewd comments about sexually harassing women.

"I don't even wait. And when you're a star they let you do it. You can do anything ... grab 'em by the pussy," Mr Trump said on the tape.

Sorry, this video has expired Donald Trump recorded having lewd conversation about women in 2005

Less than an hour later, WikiLeaks published more than 2,000 emails from the personal account of Mrs Clinton's presidential campaign chair, John Podesta.

Mrs Clinton said the release of the emails blunted the impact of the tape.

"It was covered dramatically and wall-to-wall for about 48 hours," she said.

"WikiLeaks, which in the world in which we find ourselves promised hidden information, promised some kind of secret that might be of influence, was a very clever, diabolical response to the Hollywood Access tape.

"And I've no doubt in my mind that there was some communication if not coordination to drop those the first time in response to the Hollywood Access tape."

'A lot of history' between Clinton and Assange

Mrs Clinton said that WikiLeaks' actions were motivated by Mr Assange's personal dislike of her.

"I had a lot of history with him because I was secretary of state when WikiLeaks published a lot of very sensitive information from our State Department and our Defence Department," she said.

But she said WikiLeaks had lost any claim to legitimacy.

Hillary Clinton was secretary of state when Julian Assange leaked sensitive data. ( Reuters: Peter Nicholls )

"If he's such a martyr of free speech, why doesn't WikiLeaks ever publish anything coming out of Russia? You don't see damaging, negative information coming out about the Kremlin on WikiLeaks," she said.

In response, Mr Assange said WikiLeaks' "last Russian exposé was three weeks ago" and said his organisation had a "pristine" reputation for accuracy.

Mrs Clinton warned cyber attacks had become the new normal.

"We've got to get used to the idea that cyber attacks are a really sophisticated and very difficult new form of theft," she said.

"It's [the US election] a precursor to what we will see continuing to happen in our politics or your politics or any democracy's politics, unless we figure out how to get ahead of it, and both to prevent it and mitigate it."