WASHINGTON • The US military took down a Russian troll farm last election day in a cyber attack that continued for several days after the vote, part of what US officials have said is a campaign to block and deter interference in American democracy.
The operation was intended to prevent the Internet Research Agency (IRA), based in St Petersburg, Russia, from spreading propaganda or disinformation aimed at undermining confidence in the midterm vote or the results of the election, US officials said.
The operation was aimed at taking the IRA offline for several days, from election day until the results were certified by local officials.
The IRA, the best known of the Russian troll farms that create large amounts of propaganda, has been accused by the US government of meddling in the 2016 presidential elections. It is not part of the Russian government but is controlled by oligarchs loyal to Russian President Vladimir Putin.
Intelligence agencies had assessed that the Russian troll farms that create and spread disinformation in the United States and Europe were likely to step up their disinformation activity on the day of the vote and while ballots were being counted.
Officials said the election day operations were part of a larger campaign led by US Cyber Command and the National Security Agency to secure the midterm vote.
Those operations began with a campaign of direct messages sent to Russian operatives who had created disinformation and propaganda aimed at sowing dissent and undermining confidence in US voting systems. Those direct messages were aimed at deterring the creators of propaganda.
The election day operation, reported on Tuesday by the Washington Post, was conducted under new powers authorised by the White House.
The new powers, officials said, have sped up decision-making, ensuring that bureaucratic concerns do not get in the way of taking action.
Intelligence officials have said it is difficult, if not impossible, to use cyber operations to take an adversary offline permanently.
Cyber weapons typically exploit unpatched vulnerabilities in software. Given time, the target of an operation can find workarounds or fix software problems, restoring its Internet connectivity or computer operations.
Because of that, officials said, the operations against the IRA were designed to last only for a limited number of days.
Mr Joseph Holstead, deputy director of US Cyber Command (public affairs), said the military did not "discuss classified cyberspace planning and operations".
He said: "US Cyber Command will continue to work as part of the whole-of-government effort to defend our elections and democratic institutions from foreign malign influence."
After the election, under another White House executive order, the director of national intelligence conducted an analysis of foreign interference during the event.
That report, which has not been made public, found that the Russians sought to interfere in the vote, not by trying to hack voting machines but by spreading disinformation.
The report found that Russia used social media, fake personas and Moscow-controlled media to inflame opposite ideological sides with an aim of further polarising the United States.
On Capitol Hill, intelligence committee officials declined to discuss the election day cyber operation.
But after a hearing on the rise of authoritarianism in Russia, China and elsewhere, Representative Adam Schiff, who leads the House Intelligence Committee, said Russian efforts to interfere in elections were continuing.
"There is a prioritised part of the Russian agenda to not just interfere in our democracy but also interfere in democracies in Europe," Mr Schiff said. "They are pushing their authoritarian model to undermine institutions that reinforce democracy."