Cyber attacks a bigger threat than terrorism, Clapper says

And the United States has elevated its appraisal of the cyber threat from Russia, Director of National Intelligence James Clapper said on Thursday, as he delivered the annual assessment by intelligence agencies of the top dangers facing the country.

But if there's good news, he told the Senate Armed Services Committee, it's that a catastrophic destruction of infrastructure appears to be unlikely.

"Cyber threats to U.S. national and economic security are increasing in frequency, scale, sophistication, and severity of impact," says the written assessment. "Rather than a 'Cyber Armageddon' scenario that debilitates the entire U.S. infrastructure, we envision something different. We foresee an ongoing series of low-to-moderate level cyber attacks from a variety of sources over time, which will impose cumulative costs on U.S. economic competitiveness and national security."

The assessment says officials increasingly are concerned that cyber attackers will seek to change or destroy crucial data in a way that could undermine financial markets and business confidence.

Russia, China, Iran and North Korea are the top nation-state cyber threats, the assessment says.

Beyond cyber issues, the assessment notes the existence of more terrorist safe havens than at any time in recent history.

"Unpredictable instability is the new normal," Clapper says.