While officials within the Obama administration remain reluctant to attribute the cyberattack against the Democratic National Committee (DNC) to any national government, US presidential candidate Hillary Clinton claims to "know" that Russian intelligence is the culprit.

"We know that Russian intelligence services, which are part of the Russian government, which is under the firm control of Vladimir Putin, hacked into the DNC. We know that they arranged for a lot of those emails to be released," Clinton said in an interview aired on Sunday (31 July).

Noting the alleged move by Russian intelligence services appears to have been a "deliberate effort" to influence the upcoming US presidential election, Clinton added the release of internal Democratic Party material – and the subsequent reaction of political rival Donald Trump – raises "national security" concerns.

"We know that Donald Trump has shown a very troubling willingness to back up Putin, to support Putin," she told Fox News presenter Chris Wallace.

"Whether it's saying that Nato wouldn't come to the rescue of our allies if they were invaded [or] talking about removing sanctions from Russian officials... imposed by US and Europe together, his praise for Putin, I think, is quite remarkable."

So far, the assertions of the Democratic Party of Russian involvement have not been backed up with any public evidence. For its part, the Kremlin has continued to deny the claims.

Previously, Trump raised eyebrows after appearing to plead with Russian intelligence to hack into the computer networks of the US government to locate "30,000 missing emails" of Hillary Clinton's – a statement he quickly retracted after facing cross-party backlash.

The White House, to date, has not placed blame on any specific government or hacking group. Meanwhile, as the FBI investigates, cybersecurity experts from multiple firms have linked at least two state-sponsored groups – dubbed Cosy Bear and Fancy Bear – to the infiltration.

It remains unknown if the WikiLeaks email trove was obtained from the same groups. Its founder, Julian Assange, has so far declined to comment on the source of the leak. One suspected Russian propaganda operation using the pseudonym 'Guccifer 2.0' previously claimed to have provided the data.

While many headlines have focused on the source of the information, the contents of the email release did contain a number of interesting stories – including the revelation that DNC staffers had attempted to undermine the campaign of senator Bernie Sanders, who was running against Clinton for the party nomination.

Hillary Clinton
Democratic presidential candidate former Secretary of State Hillary Clinton Justin Sullivan/Getty Images

As the evidence of Russian involvement continues to mount, other political institutions related to the Democrats have reported breaches – including the Democratic Congressional Campaign Committee (DCCC) – a group that handles donations for Democrats running for the US House of Representatives.

Most recently, Reuters reported that at least one computer network used by the Clinton campaign was also targeted by hackers. This, however, was denied by party aide Robby Mook, who told NBC's Meet The Press there was "no evidence" the campaign was breached.

Instead, Mook said hackers gained access to a "program" the Clinton campaign shares with the DNC and other government entities – but he did not elaborate on the scope of the breach. Instead, he noted, it was disturbing that "a foreign power" is "aggressively" breaking into US systems in an attempt to influence the election.

Echoing the official line from Clinton, Mook quickly spun the conversation towards the "missing emails" comments by Donald Trump, saying: "Espionage is never a laughing matter. This is a matter of national security now."