PARIS — On the eve of the most consequential French election in decades, the staff of the presidential candidate Emmanuel Macron said on Friday evening that the campaign had been targeted by a “massive and coordinated” hacking operation, one with the potential to destabilize the nation’s democracy before voters go to the polls Sunday.
The hacking, which involved a dump of campaign documents, including emails and accounting records, emerged hours before a legal prohibition on campaign communications went into effect — a prohibition that makes it extremely difficult for Macron to mitigate any damaging fallout before the runoff election, in which he faces the far-right candidate Marine Le Pen.
The hacking immediately evoked comparisons to the U.S. election, in which U.S. intelligence agencies concluded that Russia’s president, Vladimir Putin, had ordered an “influence campaign” to interfere with the election to benefit the Republican nominee, Donald Trump.
In a statement, the Macron campaign said: “Intervening in the final hour of the official campaign, this operation is clearly a matter of democratic destabilization, as was seen in the United States during the last presidential campaign.”
It said that the hackers had mixed fake documents along with authentic ones, “to sow doubt and misinformation.”
Earlier on Friday evening, Le Pen’s campaign staff said that its website had faced “regular and targeted” attacks during the campaign.
It also said that the French authorities had investigated the attacks and this week arrested “a first hacker” who was “close to extreme-left circles” and who had admitted to being responsible for several attacks on Le Pen’s campaign website. The arrest occurred on French soil, the statement said.
Unlike Macron, however, it did not appear Le Pen’s campaign documents had been stolen.
The Macron campaign said that the documents were obtained several weeks ago after the personal and professional emails of staff members at En Marche, his political movement, were hacked.
A report by a cybersecurity firm published April 24 had said that Macron had been targeted by what appeared to be the same Russian operatives responsible for hacks of Democratic campaign officials before last year’s U.S. presidential election. Security researchers at the firm, Trend Micro, said that on March 15 they spotted a hacking group they believed to be a Russian intelligence unit target Macron’s campaign — sending emails to campaign officials and others with links to fake websites designed to bait them into turning over passwords.
But the statement by Macron’s campaign on Friday night did not make it clear whether the hackers identified by Trend Micro were the same ones behind the latest attack.
Candidates and their staff are prohibited by French electoral rules to campaign from midnight on Friday until the last polls close at 8 p.m. Sunday — meaning that they cannot give interviews in the news media, hold rallies, make speeches or issue statements.
The Macron campaign made its statement at 11:56 p.m. — four minutes before the legal prohibition on campaigning went into effect.
Numerama, a French online publication focusing on digital life, said that the hacked material appeared to have been disseminated through users of 4Chan, an online bulletin board. They shared 9 gigabytes worth of documents and emails — “a jumble of what appears to be the contents of a hard drive and several emails of co-workers and En Marche political officials.”
“It will take to time to sift through it all, but at first glance, they seem to be utterly mundane,” Numerama said after analyzing the data. “One finds memos, bills, loans of amounts that are hardly over-the-top, recommendations and other reservations, amid, of course, exchanges that are strictly personal and private — personal notes on the rain and sunshine, a confirmation email for the publishing of a book, reservation of a table for friends, etc.”
Some of the documents did not appear to have any link to Macron, Numerama reported.
The National Commission for Control of the Electoral Campaign, a regulatory body, said it was contacted by the Macron campaign Friday night. The commission, which planned to meet Saturday about the hacking, urged the news media to refrain from reporting on stolen information.
“It therefore asks the media, and in particular their websites, not to report on the content of these data, recalling that the dissemination of false information is liable to fall within the scope of the law — in particular criminal law,” the commission said.
The Macron campaign appealed to journalists not to do the hackers’ bidding by widely publicizing the emails.
“We call upon the news outlets that wish to report on this operation to shoulder their responsibilities, in all good conscience,” the campaign said. “Indeed, this is not a simple hacking operation but well and truly an attempt to destabilize the French presidential election. It is therefore important to consider the nature of the leaked documents, to be fully aware of the fact that a large part of them are purely and simply fake, and the appropriateness of giving an echo to this destabilization operation.”
Gérard Araud, the French ambassador to Washington, said of the attack: “It was to be expected. The last-ditch offensive benefiting a candidacy favored by a foreign government.”
Le Pen’s campaign was not gloating, but one of her top allies, Florian Philippot, the vice president of the National Front, asked: “Will the #Macronleaks learn things that investigative journalism has deliberately killed,” referring to his argument that the mainstream news media has been biased against Le Pen. “Scary, this democratic shipwreck.” Macron, 39, an independent centrist and a former economy minister who is making his first run for elected office, has been favored in the polls over Le Pen, 48, a lawyer and political heir to the movement her father, now estranged, founded in 1972.
On Wednesday, the two candidates confronted each other head-to-head in a vicious debate that more resembled an American-style shoutfest than the Descartian discourse that French voters are more accustomed to. Le Pen, who was relentless in her attacks, was widely judged the loser.
A post-debate poll, by the firm Ipsos — which was very accurate in its projections before the first round of the elections on April 23 — found Macron’s lead over Le Pen had widened, 63 percent to 37 percent.
But Le Pen could benefit on Sunday if poor and disaffected suburban voters stay home, or if on-the-fence voters who are unenthusiastic about their choices decide to abstain.