Hackers believed to be working for the Russian government violated the Democratic National Committee's network, and spied internal communication by capturing data from Democratic presidential candidate Donald Trump.
Two separate groups reportedly have entered the DNC system, managing to read all emails and watch chat communications for almost a whole year before being identified, according to CrowdStrike Security Company, which has undertaken to correct security gaps.
Russian spies also watched the networks of presidential candidate Hillary Clinton, as well as the computers of some Republican political action committees, according to a Washington Post publication.
A spokesman for the Russian government denied all involvement in the violations.
"We completely exclude the possibility that the government or state actors are involved (Russian) in it," Kremlin spokesman Dmitry Peskov told Reuters in Moscow.
The invasion is indicative of the complexity of the technique of Russian hackers, which intelligence officials have long considered them to be the most talented ones.
The Democratic Party has reportedly been aware of the hackers' attempts to smuggle Trump material for two months, and even the US secret services have been involved in trying to find out who was behind hacking, a source familiar with the opposition study said.
The same source reported that agents of the Democratic Party believed that the hack was carried out by the Russian government.
Internet attacks on political candidates and organizations are common all over the world. NSA chief James Clapper said last month that he was aware of hacking attempts in campaigns and he was expecting more to be discovered by 8 in November for the presidential election.
The first group, CrowdStrike called Cozy Bear, entered the DNC systems last summer. He mainly watched email and chat conversations, and hackers could work for the Russian Federal Security Service, or FSB.
The second group was named Fancy Bear, and they are likely to work on behalf of Russian soldiers. The team managed to gain access at the end of April and "went straight to the OPPO ... for Donald Trump."
Let's mention that in the last two US presidential rounds, 2008 and 2012, there was a barrage of cyber attacks by many opponents who were targeting President Barack Obama's campaign and his Republican rival campaign.
US intelligence officials have reported that many previous attacks have been linked to Chinese hackers.