Russia presents greatest threat to US: FBI chief

Washington: Russia presents greatest threat to American national security, FBI Director James Comey has told lawmakers.

"Certainly in my view, (Russia presents) the greatest threat of any nation on earth, given their intention and their capability," Comey said in response to a question during his testimony before the Senate Judiciary Committee, where lawmakers expressed concern over Russian activities in the cyberspace.

Comey said "yes" when Senator Lindsey Graham asked when it comes to Russia, is it fair to say that Russia actively provides safe haven to cyber criminals.

He said "it is a fair statement," when Senator Lindsey Graham asked if he agreed with him the only way the Russians are going to stop this for them to pay a price for interfering in the US political process.

Comey said that Russians are doing this all over the world.

The FBI chief said that in the last presidential elections, the Russians were not able to change the actual vote tally, but one day they might.

"We found no indication of any change in vote tallies. There was efforts aimed at voter registration systems, but I suppose in theory, part of the US. The beauty of our system is it's a bit of a hairball. All different kinds of systems," he said.

"My understanding is they have attempted it in other countries," Comey said in response to another question from Graham.

In his remarks, Senator Chuck Grassley, Chairman of the Senate Judiciary Committee and the Ranking Member Senator Diana Feinstein expressed concern over Russian cyber activities.

Comey said the FBI has been working against Russian hackers.

"Last month, the FBI working with our partners with the Spanish national police took down a botnet called the Kelihos botnet and locked up the Russian hacker behind that botnet, who made a mistake that Russian criminals sometimes make of leaving Russia and visiting the beautiful city of Barcelona," he said.

"He is now in jail in Spain and the good people's computers who had been lashed to that zombie army have now been freed from it and are no longer part of a huge criminal enterprise," he added.

Comey said the intelligence community with high confidence concluded it was Russia that hacked into the Democratic party servers.

"In many circumstances, it's hard to do attribution of a hack, but sometimes the intelligence is there. We have high confidence that the North Koreans hacked Sony, we have high confidence that the Russians did the hacking of the DNC and the other organisations," he said.