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US special counsel Robert Mueller has filed charges against Russian hackers tied to cyberattacks on the Democratic National Committee.

The indictments, part of Mueller's investigation into Russian meddling in the 2016 election, were announced by US Deputy Attorney General Rod Rosenstein during a Justice Department press conference on Friday morning. Rosenstein said the hackers intended to interfere with the presidential election but noted no evidence had been found to suggest the cyberattacks affected the outcome.

"The Internet allows foreign adversaries to attack America in new and unexpected ways. Free and fair elections are hard-fought and contentious," Rosenstein said. "There will always be adversaries who work to exacerbate domestic differences and try to confuse, divide, and conquer us."

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The indictments come as President Donald Trump is set to meet with Russian leader Vladimir Putin on Monday. Rosenstein said he had briefed Trump on the charges earlier this week, and the president is fully aware of the indictment.

"Today's charges include no allegations of knowing involvement by anyone on the campaign and no allegations that the alleged hacking affected the election result," the White House said in a statement.

The Russian hacking campaign had been going on since March 2016, with hundreds of files containing malware infiltrating the Democratic National Committee's servers, according to the indictment.

The DNC suffered a series of cyberattacks during 2016, with tens of thousands of stolen emails subsequently posted on WikiLeaks, as well as DCLeaks, a site the Russian hackers created using fake personas.

All 12 defendants are a part of Russia's military intel agency, the GRU. The Russian hackers registered the domain name "DCLeaks.com" and released thousands of stolen emails they obtained through spearphishing DNC members, according to the indictment.

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The Russian military officers are also accused of creating "Guccifer 2.0," who posed as a lone hacker from Romania.

"Both were created and controlled by the Russian GRU," the deputy attorney general said.

The Guccifer 2.0 persona had been in regular contact with senior members of the Trump presidential campaign, according to the indictment. The court documents also showed that a Congressional candidate requested stolen documents from Guccifer 2.0.

In a tweet, Rudy Giuliani, who is on President Trump's legal team, said the indictment was "good news for all Americans." The former New York mayor said that no Americans were involved though the indictment described the actions of several Americans.

The indictments Rod Rosenstein announced are good news for all Americans. The Russians are nailed. No Americans are involved. Time for Mueller to end this pursuit of the President and say President Trump is completely innocent. — Mayor Rudy Giuliani (@RudyGiuliani) July 13, 2018

Sen. Mark Warner, the vice chairman of the Senate Select Committee on Intelligence, called for Trump to cancel his meeting with Putin in response to the indictment.

"As today's indictment makes crystal clear, tensions between our two nations exist because Russia attacked our democracy," the Democrat from Virginia said in a statement.

The operation had Russian agents dedicated to different teams, some responsible for targeting the DNC, while others were behind attacks against the Clinton campaign, prosecutors said. The spearphishing effort created a page designed to look like a security notification from Google, and asked victims to type in their password.

The ploy granted the hackers access to an account owned by John Podesta, who was the Clinton campaign chairman at the time. The Russian agents allegedly stole 50,000 of Podesta's emails.

The operation was funded through cryptocurrencies including bitcoin. In one case, the Russian hackers allegedly paid more than $95,000 to buy servers, prosecutors said.

They also installed malware to spy on DNC members, Rosenstein said. This allowed them to record keystrokes and take screenshots on hacked devices, the deputy attorney general said.

The malware, which was on at least 10 different DNC computers, allowed hackers to monitor computer activity, steal passwords and have access to the party's network for at least two months.

"The defendants accessed email accounts of volunteers and employees of a US presidential campaign," Rosenstein said at the press conference.

Despite cleaning efforts after DNC staffers realized they were hacked, the malware remained on computers until October 2016, prosecutors said.

Along with attacks on the DNC, the Justice Department said the Russian GRU officers hacked a state election board's website and stole data on about 500,000 voters. The alleged hackers also targeted state and local election officials with emails packed with malware.

After hacking computers, the Russian officers searched for terms including "Hillary," "Cruz," "Trump" and "Benghazi Investigations."

In February, the Justice Department indicted 13 Russian nationals and the Internet Research Agency for its propaganda campaign spread across social media during the 2016 election.

You can read the full indictment here:

Updated at 9:21 a.m. PT: To include remarks from Deputy Attorney General Rod Rosenstein, at 9:31 a.m.: To include the full indictment, at 9:57 a.m.: To include details from court documents, at 10:05 a.m.: To include reactions from the Trump legal team, at 10:54 a.m.: To include a statement from the White House, 12:17 p.m.: To add remarks from Sen. Mark Warner.