Updated

The campaign of French presidential candidate Emmanuel Macron said it suffered a "massive and coordinated" hacking attack and document leak that it called a bid to destabilize Sunday's presidential runoff.

Fears of hacking, fake news manipulation and Russian meddling clouded the French campaign but had largely gone unrealized — until late Friday's admission by Macron's campaign that it had suffered a coordinated online pirate attack had led to the leak of campaign emails and financial documents. It was unclear who was behind the hack and the leak.

U.S. intelligence agencies said they have definitive evidence that Russia was behind the hacking of Democratic email accounts, with the aim of benefiting Donald Trump's campaign and harming his Democratic opponent, Hillary Clinton.

Putin has long denied such claims. On Tuesday, during a tense meeting with German Chancellor Angela Merkel, the Russian president was forced to, again, deny reports of Russian meddling in international elections.

Merkel said she was confident that Germany can weather any disinformation campaign targeting Germany's upcoming election. Asked about the threat during the news conference, she cited two recent incidents of what she described as "gross misinformation."

Macron’s far-right rival Marine Le Pen, meanwhile, told The Associated Press that she believes she can pull off a surprise victory in the high-stakes vote that could change Europe's direction.

A campaign blackout starting minutes after the Macron team announcement means that Le Pen's campaign can't legally comment on the leak.

In a statement, Macron's En Marche movement said the hack took place a few weeks ago, and that the leaked documents have been mixed with false documents to "seed doubt and disinformation" and destabilize Sunday's presidential runoff. Hillary Clinton's U.S. presidential campaign suffered similar leaks, and also said that authentic documents were mixed with false documents.

The timing of the leak could be seen as either bizarre or inspired.

The documents' release just before France enters a roughly two-day-long blackout - during which politicians, journalists and even ordinary citizens are meant to pull back from any public election talk to avoid swaying the vote - means that the leak may have very little impact beyond the overheated world of Twitter and Reddit.

On the other hand, the messages' release just before France's political machinery shuts down for the weekend might mean that talk of the leak - regardless of its veracity - will dominate dinner table conversations as French voters make up their minds Saturday.

The candidates stopped campaigning at midnight Friday to give voters a day of reflection before the election. It's a stark choice: Le Pen's anti-immigration, anti-European Union platform, or Macron's progressive, pro-EU stance.

Tensions marred the race right to the end.

France's presidential voting watchdog called on the Interior Ministry late Friday to look into claims by the Le Pen campaign that ballot papers are being tampered with nationwide to benefit Macron. The Le Pen campaign said electoral administrators in several regions who receive ballot papers for both candidates have found the Le Pen ballot "systematically torn up."

Earlier in the day, anti-Le Pen crowds disrupted her visit to a renowned cathedral in Reims.

The presidential campaign has been unusually bitter, with voters hurling eggs and flour, protesters clashing with police and candidates insulting each other on national television — a reflection of the widespread public disaffection with politics as usual.

In an interview with The Associated Press in the final hours of a hostile, topsy-turvy campaign, Le Pen said that win or lose, "we changed everything." She claimed an "ideological victory" for her populist, anti-immigrant worldview.

"Even if we don't reach our goal, in any event there is a gigantic political force that is born," she told AP in her campaign headquarters. Her party "imposed the overhaul" of French politics and set the tone of the election, she said.

The 39-year-old Macron, too, played a key role in upending France's traditional political structure with his wild-card campaign.

Voters liked the idea, and chose Macron and Le Pen in the first-round vote, dumping the traditional left and right parties that have governed modern France. Le Pen said those parties have been "blackballed."

Many voters, however, don't like either Le Pen or Macron. They fear her party's racist past, while worrying that his platform would demolish worker job protections or be too much like his mentor, the deeply unpopular outgoing President Francois Hollande.

Students protested both presidential candidates Friday by blocking high schools and marching through Paris.

Le Pen, who was pelted with eggs Thursday in Brittany, was met by hecklers Friday at the Reims cathedral. She left via an unmarked door, putting her arms over her head as if to protect herself and diving into a black car.

In the AP interview, Le Pen said she was confident she can bring the divided country together if elected.

"Yes. I want most of all to put democracy back in place ... we must re-weave the links among people." She said.

Macron would worsen divisions, she claimed.

The pro-business Macron, who topped all vote-getters in the first-round, also has been booed and heckled frequently as he visited blue-collar workers.

Violent protests erupted in Paris earlier this week against both candidates, with several police officers injured. And critics decried the bitter tone of Wednesday night's presidential debate.

Le Pen acknowledged to AP that she became angry at the debate but said she was merely channeling the mood of France. Macron acknowledged the French are exasperated by the government's ineffectiveness, but he dismissed Le Pen's vision of an infuriated country.

She "speaks for no one. ... Madame Le Pen exploits anger and hatred," Macron told RTL radio.

The Associated Press contributed to this report