Cyber attacks declared major threat to US security

Cyber crime tops the list of worldwide threats to US security, according to the latest report from its National Intelligence agency.

Russia and China present large challenges to America's digital future, while Iran and North Korea are "unpredictable", according to The Worldwide Threat Assessment report.

Director of National Intelligence, James Clapper, warned Russia is developing its own cyber command centre, which could have offensive capabilities, and claimed the country's spies are targeting sensitive US data.

He also accused China of stealing intellectual property and exploiting computer networks.

Particular threats highlighted included distributed-denial-of-service (DDoS) attacks, where an overwhelming number of network access requests crash a server, as well as malware capable of deleting data.

The health sector's increasing reliance on connected devices and cyber networks could put it at risk of attacks, said Clapper, while 3D printing could revolutionise underground criminal activity.

Several high profile attacks on US infrastructure have taken place in the last year, with Sony Pictures studio falling victim to a massive data breach that saw hackers make off with ten terabytes of data last November.

That included entire films, embarrassing company emails and staff's personal details.

While the FBI claimed North Korea was behind the attack, it's not actually clear who the perpetrators were.

One example cited by Clapper was a series of widespread DDoS attacks against the US banking sector starting in September 2012, affecting institutions including JP Morgan, Citigroup and Bank of America.

The hacks took their websites offline, and congressional committees claimed Iran was the source.