Leading French presidential candidate Emmanuel Macron ’ s campaign said on Friday it had been the target of a “ massive ” computer hack Attack.Databreach that dumped Attack.Databreach its campaign emails online 1-1/2 days before voters choose between the centrist and his far-right rival , Marine Le Pen . Macron , who is seen as the frontrunner in an election billed as the most important in France in decades , extended his lead over Le Pen in polls on Friday . As much as 9 gigabytes of data were posted on a profile called EMLEAKS to Pastebin , a site that allows anonymous document sharing . It was not immediately clear who was responsible for posting the data or if any of it was genuine . In a statement , Macron ’ s political movement En Marche ! ( Onwards ! ) confirmed that it had been hacked . “ The En Marche Movement has been the victim of a massive and co-ordinated hack Attack.Databreach this evening which has given rise to the diffusion on social media of various internal information , ” the statement said . An interior ministry official declined to comment , citing French rules that forbid any commentary liable to influence an election , which took effect at midnight on Friday ( 2200 GMT ) . The presidential election commission said in statement that it would hold a meeting later on Saturday after Macron ’ s campaign informed it about the hack Attack.Databreach and publishing of the data . Former economy minister Macron ’ s campaign has previously complained about attempts to hack Attack.Databreach its emails , blaming Russian interests in part for the cyber attacks Attack.Databreach . On April 26 , the team said it had been the target of a attempts to steal Attack.Databreach email credentials dating back to January , but that the perpetrators had failed to compromise Attack.Databreach any campaign data . The Kremlin has denied it was behind any such attacks , even though Macron ’ s camp renewed complaints against Russian media and a hackers ’ group operating in Ukraine . Vitali Kremez , director of research with New York-based cyber intelligence firm Flashpoint , told Reuters his review indicates that APT 28 , a group tied to the GRU , the Russian military intelligence directorate , was behind the leak . He cited similarities with U.S. election hacks that have been previously attributed to that group . APT28 last month registered decoy Attack.Phishing internet addresses to mimic Attack.Phishing the name of En Marche , which it likely used send Attack.Phishing tainted emails to hack into the campaign ’ s computers , Kremez said . Those domains include onedrive-en-marche.fr and mail-en-marche.fr . “ If indeed driven by Moscow , this leak appears to be a significant escalation over the previous Russian operations aimed at the U.S. presidential election , expanding the approach and scope of effort from simple espionage efforts towards more direct attempts to sway the outcome , ” Kremez said . France is the latest nation to see a major election overshadowed by accusations of manipulation through cyber hacking . En Marche said the documents only showed the normal functioning of a presidential campaign , but that authentic documents had been mixed on social media with fake ones to sow “ doubt and misinformation ” . Ben Nimmo , a UK-based security researcher with the Digital Forensic Research Lab of the Atlantic Council think tank , said initial analysis indicated that a group of U.S. far-right online activists were behind early efforts to spread the documents via social media . They were later picked up and promoted by core social media supporters of Le Pen in France , Nimmo said . The leaks emerged on 4chan , a discussion forum popular with far right activists in the United States . An anonymous poster provided links to the documents on Pastebin , saying , “ This was passed on to me today so now I am giving it to you , the people . ”