The indictment charges 13 Russian nationals and three businesses - including an Internet firm tied to the Kremlin - with conspiracy, identity theft, failing to register as foreign agents and violating laws that limit the use of foreign money in us elections.
Three of those named have also been accused of conspiracy to commit wire fraud and five have been accused of aggravated identity theft. The surprise 37-page indictment could alter the divisive United States domestic debate over Russia's meddling, undercutting some Republicans who, along with Trump, have attacked Mueller's investigation.
In comments to Russian state news agency RIA Novosti, Prigozhin dismissed the indictment.
McMaster also pointedly rejected an idea floated by Trump in a tweet in July in which he said he had discussed with Russian President Vladimir Putin "forming an impenetrable Cyber Security Unit.so that election hacking, & many other negative things, will be guarded".
In his announcement of the indictments, Deputy Attorney General Rod Rosenstein said that the indictment makes no allegation that "any American had any knowledge" of the meddling scheme.
The indictment charges 13 Russians with running a huge but hidden social media trolling campaign aimed in part at helping Republican Trump defeat Democrat Hillary Clinton.
None of the 13 Russian suspects are in USA custody. U.S. president later tweeted that his team did not collude with Moscow. "These indictments now say it also violated the law".
The indictment charges that the foreigners falsely posed as US citizens, stole identities and otherwise engaged in fraud and deceit in an effort to influence the USA political process, including the 2016 presidential race.
And it indicates the investigation includes looking into whether Russian Federation meddled in the run-up to the elections, following a string of charges relating to the actions of Trump associates.
"They engaged in operations primarily meant to communicate derogatory information about Hillary Clinton, to denigrate other candidates such as Ted Cruz and Marco Rubio, and to support Bernie Sanders and then-candidate Donald Trump", the indictment states.
It called the allegations "absurd".
The record of U.S. intelligence, which is no stranger to providing "completely fabricated" intel, does not lend much credibility to the "intelligence assessments" over the Kremlin's alleged role in the election, Black said. "13 against the billions' budgets of the secret services?" she asked in a Facebook post. Against espionage and counter-espionage, against new developments and technologies?
"Americans are very impressionable people", he was quoted as saying. "I don't think it was brilliantly thought out, but they put an army out there to do what they can". I'm not at all upset that I'm on this list. "They see what they want to see". If we are now in pursuit of social media players, are the hackers who broke into the DNC and John Podesta's emails in sight?
"We know we have more to do to prevent against future attacks", said Joel Kaplan, vice president of global policy at Facebook, in a statement. "That's why they are just children's statements", Andrei Kutskikh, the presidential envoy for worldwide information security, told Russian state news agency RIA Novosti.
What is the investigation about?
The reportedly Russian-organized "Trump is NOT my president" rally, which took place in New York City on November 12, 2016, was "clearly meant to divide American and bring American democracy to its knees".
In May a year ago, Mueller was appointed special counsel to investigate whether anyone from his campaign colluded in the effort.
The 13 individuals and three entities indicted on February 16 join the four former members of the Trump campaign - George Papadopoulos, Rick Gates, Paul Manafort, and Mike Flynn - who have already faced charges and plead guilty on charges relating to Mueller's Russian Federation investigation.
A business associate of his, Rick Gates, was also charged with conspiracy to launder money.
By August, the Russian group had moved its sights to Florida, a key swing state, again using false IDs to contact Trump campaign staff involved in Florida activities. Trump and his legal team should be exceptionally anxious about what else Mueller has.
Trump has been accused by opponents of trying to interfere with the investigation, which he denies.