An illustration picture shows a projection of binary code on a man holding a laptop computer, in an office in Warsaw June 24, 2013. REUTERS/Kacper Pempel 

A man is seen near cyber code and the U.S. National Security Agency logo in this photo illustration taken in Sarajevo March 11, 2015. NSA was sued on March 10, 2015, by Wikimedia and other groups challenging one of its mass surveillance programs that they said violates Americans' privacy and makes individuals worldwide less likely to share sensitive information. REUTERS/Dado Ruvic (BOSNIA AND HERZEGOVINA - Tags: SCIENCE TECHNOLOGY POLITICS) 

Part of the building of 'Unit 61398', a secretive Chinese military unit, is seen in the outskirts of Shanghai February 19, 2013. The unit is believed to be behind a series of hacking attacks, a U.S. computer security company said, prompting a strong denial by China and accusations that it was in fact the victim of U.S. hacking. REUTERS/Carlos Barria 

A man types on a computer keyboard in Warsaw in this February 28, 2013 illustration file picture. One of the largest ever cyber attacks is slowing global internet services after an organisation blocking "spam" content became a target, with some experts saying the disruption could get worse. To match INTERNET-ATTACK/ REUTERS/Kacper Pempel/Files 

A photo illustration shows a USB device being plugged into a laptop computer in Berlin July 31, 2014. USB devices such as mice, keyboards and thumb-drives can be used to hack into personal computers in a potential new class of attacks that evade all known security protections, German crypto specialist and chief scientist with Berlin's SR Labs Karsten Nohl revealed on Thursday. REUTERS/Thomas Peter 

A lock icon, signifying an encrypted Internet connection, is seen on an Internet Explorer browser in a photo illustration in Paris April 15, 2014. About two thirds of all websites use code known as OpenSSL to help secure those encrypted sessions. Researchers last week warned they have uncovered a security bug in OpenSLL dubbed Heartbleed, which could allow hackers to steal massive troves of information without leaving a trace. REUTERS/Mal Langsdon 

A sign is pictured in the hallway of the Microsoft Cybercrime Center, the new headquarters of the Microsoft Digital Crimes Unit, in Redmond, Washington November 11, 2013. Microsoft, the maker of the most popular computer operating system in the world is launching a new strategy against criminal hackers by bringing together security engineers, digital forensics experts and lawyers trained in fighting software pirates under one roof at its new Cybercrime Center. Picture taken November 11, 2013. To match Feature MICROSOFT-CYBERCRIME/ REUTERS/Jason Redmond 

A sign is pictured in the hallway of the Microsoft Cybercrime Center, the new headquarters of the Microsoft Digital Crimes Unit, in Redmond, Washington November 11, 2013. Microsoft, the maker of the most popular computer operating system in the world is launching a new strategy against criminal hackers by bringing together security engineers, digital forensics experts and lawyers trained in fighting software pirates under one roof at its new Cybercrime Center. Picture taken November 11, 2013. To match Feature MICROSOFT-CYBERCRIME/ REUTERS/Jason Redmond 

Vishant Patel, senior manager of investigations at the Microsoft Digital Crimes Unit, shows a heat map and talks about how malicious computer networks known as the Citadel Botnets attack computers in Western Europe at the Microsoft Cybercrime Center in Redmond, Washington November 11, 2013. Microsoft, the maker of the most popular computer operating system in the world is launching a new strategy against criminal hackers by bringing together security engineers, digital forensics experts and lawyers trained in fighting software pirates under one roof at its new Cybercrime Center. Picture taken November 11, 2013. To match Feature MICROSOFT-CYBERCRIME/ REUTERS/Jason Redmond 

A magnifying glass is held in front of a computer screen in this picture illustration taken in Berlin May 21, 2013. The Financial Times' website and Twitter feeds were hacked May 17, 2013, renewing questions about whether the popular social media service has done enough to tighten security as cyber-attacks on the news media intensify. The attack is the latest in which hackers commandeered the Twitter account of a prominent news organization to push their agenda. Twitter's 200 million users worldwide send out more than 400 million tweets a day, making it a potent distributor of news. REUTERS/Pawel Kopczynski 

A journalist checks the U.S. Senate's website after it was attacked by internet hackers in Washington June 13, 2011. The U.S. Senate's website was hacked over the weekend, leading to a review of all of its websites, in the latest embarrassing breach of security to hit a major U.S. Government institution. The Pentagon is about to roll out an expanded effort to safeguard its contractors from hackers and is building a virtual firing range in cyberspace to test new technologies, according to officials familiar with the plans, as a recent wave of cyber attacks boosts concerns about U.S. vulnerability to digital warfare. The twin efforts show how President Barack Obama's administration is racing on multiple fronts to plug the holes in U.S. cyber defenses. To match Special Report USA-CYBERSECURITY/ REUTERS/Stelios Varias 

John Bumgarner, a cyber warfare expert who is chief technology officer of the U.S. Cyber Consequences Unit, a non-profit group that studies the impact of cyber threats, holds a notebook computer while posing for a portrait in Charlotte December 1, 2011. A cyber warfare expert claims he has linked the Stuxnet computer virus that attacked Iran's nuclear program in 2010 to Conficker, a mysterious worm that surfaced in late 2008 and infected millions of PCs. Conficker was used to open back doors into computers in Iran, then infect them with Stuxnet, according to research Bumgarner, a retired U.S. Army special-operations veteran and former intelligence officer. To match Insight - CYBERSECURITY/IRAN REUTERS/John Adkisson 

An analyst looks at code in the malware lab of a cyber security defense lab at the Idaho National Laboratory in Idaho Falls, Idaho September 29, 2011. REUTERS/Jim Urquhart 

A hacker, who requests not to have his name revealed, works on his laptop in his office in Taipei July 10, 2013. Taiwan is the frontline in an emerging global battle for cyberspace, according to elite hackers in the island's IT industry, who say it has become a rehearsal area for the Chinese cyberattacks that have strained ties with the United States. The self-governing island, they say, has endured at least a decade of highly-targeted data-theft attacks that are then directed towards larger countries. Picture taken July 10, 2013. REUTERS/Pichi Chuang 

2Lt William Liggett (L) talks with a colleague as a map is displayed on one of the screens at the Air Force Space Command Network Operations & Security Center at Peterson Air Force Base in Colorado Springs, Colorado July 20, 2010. U.S. national security planners are proposing that the 21st century's critical infrastructure -- power grids, communications, water utilities, financial networks -- be similarly shielded from cyber marauders and other foes. The ramparts would be virtual, their perimeters policed by the Pentagon and backed by digital weapons capable of circling the globe in milliseconds to knock out targets. To match Special Report USA-CYBERWAR/ REUTERS/Rick Wilking