Computer network equipment is seen in a server room in Vienna, Austria, October 25, 2018. REUTERS/Heinz-Peter Bader

Computer network equipment is seen in a server room in Vienna, Austria, October 25, 2018. REUTERS/Heinz-Peter Bader

Computer network equipment is seen in a server room in Vienna, Austria, October 25, 2018. REUTERS/Heinz-Peter Bader

Computer network equipment is seen in a server room in Vienna, Austria, October 25, 2018. REUTERS/Heinz-Peter Bader

Computer network equipment is seen in a server room in Vienna, Austria, October 25, 2018. REUTERS/Heinz-Peter Bader

A "Mining rig" computer server is pictured in Bitminer Factory in Florence, Italy, April 6, 2018. Picture taken April 6, 2018. REUTERS/Alessandro Bianchi

Bitcoin mining computer servers are seen in Bitminer Factory in Florence, Italy, April 6, 2018. Picture taken April 6, 2018. REUTERS/Alessandro Bianchi

A "Mining rig" computer server is pictured in Bitminer Factory in Florence, Italy, April 6, 2018. Picture taken April 6, 2018. REUTERS/Alessandro Bianchi

Bitcoin mining computer servers are seen in Bitminer Factory in Florence, Italy, April 6, 2018. Picture taken April 6, 2018. REUTERS/Alessandro Bianchi

LAN network cables plugged into a Bitcoin mining computer server are pictured in Bitminer Factory in Florence, Italy, April 6, 2018. Picture taken April 6, 2018. REUTERS/Alessandro Bianchi

Cables plugged into a Bitcoin mining computer server are pictured in Bitminer Factory in Florence, Italy, April 6, 2018. Picture taken April 6, 2018. REUTERS/Alessandro Bianchi

An employee works on a "Mining rig" computer server in Bitminer Factory in Florence, Italy, April 6, 2018. Picture taken April 6, 2018. REUTERS/Alessandro Bianchi

Employees talk outside a room with stacks of computer servers at the BMIT Data Centre in SmartCity Malta in Kalkara, Malta, June 22, 2017. Picture taken June 22, 2017. REUTERS/Darrin Zammit Lupi

Computer servers are seen at the headquarters of the Wnet internet service provider in Kiev, Ukraine July 26, 2017. Picture taken July 26, 2017. REUTERS/Valentyn Ogirenko

LAN network cables plugged into a computer server in Singapore July 26, 2017. REUTERS/Thomas White

LAN network cables plugged into a computer server in Singapore July 26, 2017. REUTERS/Thomas White

Computer servers in Singapore July 26, 2017. REUTERS/Thomas White

Network cables plugged into a computer server in Singapore July 26, 2017. REUTERS/Thomas White

A computer server in Singapore July 26, 2017. REUTERS/Thomas White

LAN network cables plugged into a computer server in Singapore July 26, 2017. REUTERS/Thomas White

Computer servers in Singapore July 26, 2017. REUTERS/Thomas White

Computer servers are part of the decoration of a shop window of luxury brand Chanel in downtown Frankfurt, Germany, April 7, 2017. REUTERS/Kai Pfaffenbach

House Oversight and Government Reform Committee Chairman Jason Chaffetz (R-UT) listens to testimony from computer technician Justin Cooper (NOT SHOWN) during a committee hearing about the private email server of Democratic presidential nominee Hillary Clinton, used during her tenure as Secretary of State, on Capitol Hill in Washington, U.S., September 13, 2016. REUTERS/Jonathan Ernst

House Oversight and Government Reform Committee Chairman Jason Chaffetz (R-UT) listens to testimony from computer technician Justin Cooper (NOT SHOWN) during a committee hearing about the private email server of Democratic presidential nominee Hillary Clinton, used during her tenure as Secretary of State, on Capitol Hill in Washington, U.S., September 13, 2016. REUTERS/Jonathan Ernst

Platte River Networks computer technician Paul Combetta (C) departs with his attorneys after invoking his constitutional right not to incriminate himself at a hearing of the House Oversight and Government Reform Committee about the private email server of Democratic presidential nominee Hillary Clinton, used during her tenure as Secretary of State, on Capitol Hill in Washington, U.S. September 13, 2016. REUTERS/Jonathan Ernst

Chairman Jason Chaffetz (R-UT), flanked by ranking member Representative Elijah Cummings (D-MD) (L), listens to testimony from computer technician Justin Cooper (obscured, back to camera) during a hearing of the House Oversight and Government Reform Committee about the private email server of Democratic presidential nominee Hillary Clinton, used during her tenure as Secretary of State, on Capitol Hill in Washington, U.S. September 13, 2016. REUTERS/Jonathan Ernst

People arrive at Kiev's main airport, Boryspil, in Ukraine, January 18, 2015. Ukrainian authorities will review the defences of government computer systems, including at airports and railway stations, after a cyber attack on Kiev's main airport was launched from a server in Russia, officials told Reuters on Monday. REUTERS/Valentyn Ogirenko

Passengers get registered at Kiev's main airport, Boryspil, in Ukraine, January 18, 2015. Ukrainian authorities will review the defences of government computer systems, including at airports and railway stations, after a cyber attack on Kiev's main airport was launched from a server in Russia, officials told Reuters on Monday. REUTERS/Valentyn Ogirenko

A general view shows Kiev's main airport, Boryspil, in Ukraine, January 18, 2015. Ukrainian authorities will review the defences of government computer systems, including at airports and railway stations, after a cyber attack on Kiev's main airport was launched from a server in Russia, officials told Reuters on Monday. REUTERS/Valentyn Ogirenko

An IBM product manager stands in front of an IBM z13 mainframe server at the CeBIT trade fair in Hanover March 14, 2015. The world's biggest computer and software fair will open to the public from March 16 to 20. REUTERS/Morris Mac Matzen (GERMANY - Tags: BUSINESS SCIENCE TECHNOLOGY)

Picture shows the cooling system of an IBM z13 mainframe server on IBM stand at the CeBIT trade fair in Hanover March 14, 2015. The world's biggest computer and software fair will open to the public from March 16 to 20. REUTERS/Morris Mac Matzen (GERMANY - Tags: BUSINESS SCIENCE TECHNOLOGY)

Ethernet cables used for internet connections are pictured in a Berlin office, August 20, 2014. The German cabinet discussed on Wednesday Germany's digital agenda for the future. REUTERS/Fabrizio Bensch (GERMANY - Tags: POLITICS)

Ethernet cables used for internet connections are pictured in a Berlin office, August 20, 2014. The German cabinet discussed on Wednesday Germany's digital agenda for the future. REUTERS/Fabrizio Bensch (GERMANY - Tags: POLITICS)

A man watches a server at the booth of IBM during preparations for the CeBIT trade fair in Hanover, March 9, 2014. The world's biggest computer and software fair will be open to the public from March 10 to 14. REUTERS/Fabrizio Bensch (GERMANY - Tags: BUSINESS TELECOMS SCIENCE TECHNOLOGY)

A technician works at a server in front of a big data analytics logo at the booth of IBM during preparations for the CeBIT trade fair in Hanover, March 9, 2014. The world's biggest computer and software fair will be open to the public from March 10 to 14. REUTERS/Fabrizio Bensch (GERMANY - Tags: BUSINESS TELECOMS SCIENCE TECHNOLOGY)

Protonet servers stand on a work bench at the headquarters of German company Protonet in Hamburg January 30, 2014. Protonet and many other start-ups in the country offer data security "made in Germany" after former U.S. National Security Agency contractor Edward Snowden alleged the NSA is engaged in industrial espionage and put software in almost 100,000 computers around the world. Picture taken January 30. TO GO WITH STORY DEUTSCHLAND-STARTUPS-NSA/ REUTERS/Fabian Bimmer (GERMANY - Tags: SCIENCE TECHNOLOGY BUSINESS TELECOMS)

Protonet servers stand on a work bench at the headquarters of German company Protonet in Hamburg January 30, 2014. Protonet and many other start-ups in the country offer data security "made in Germany" after former U.S. National Security Agency contractor Edward Snowden alleged the NSA is engaged in industrial espionage and put software in almost 100,000 computers around the world. Picture taken January 30. TO GO WITH STORY DEUTSCHLAND-STARTUPS-NSA/ REUTERS/Fabian Bimmer (GERMANY - Tags: SCIENCE TECHNOLOGY BUSINESS TELECOMS)

Parts of the cooling system of a Protonet server stand on a work bench at the headquarters of German company Protonet in Hamburg January 30, 2014. Protonet and many other start-ups in the country offer data security "made in Germany" after former U.S. National Security Agency contractor Edward Snowden alleged the NSA is engaged in industrial espionage and put software in almost 100,000 computers around the world. Picture taken January 30. TO GO WITH STORY DEUTSCHLAND-STARTUPS-NSA/ REUTERS/Fabian Bimmer (GERMANY - Tags: SCIENCE TECHNOLOGY BUSINESS TELECOMS)

The motherboard of a Protonet server stands on a work bench at the headquarters of German company Protonet in Hamburg January 30, 2014. Protonet and many other start-ups in the country offer data security "made in Germany" after former U.S. National Security Agency contractor Edward Snowden alleged the NSA is engaged in industrial espionage and put software in almost 100,000 computers around the world. Picture taken January 30. TO GO WITH STORY DEUTSCHLAND-STARTUPS-NSA/ REUTERS/Fabian Bimmer (GERMANY - Tags: SCIENCE TECHNOLOGY BUSINESS TELECOMS)

Data links are seen on the backside of a Protonet server on a work bench at the headquarter of German company Protonet in Hamburg January 30, 2014. Protonet and many other start-ups in the country offer data security "made in Germany" after former U.S. National Security Agency contractor Edward Snowden alleged the NSA is engaged in industrial espionage and put software in almost 100,000 computers around the world. Picture taken January 30. TO GO WITH STORY DEUTSCHLAND-STARTUPS-NSA/ REUTERS/Fabian Bimmer (GERMANY - Tags: SCIENCE TECHNOLOGY BUSINESS TELECOMS)

Co-founder of German company Protonet, Ali Jelveh, poses with a server at their headquarters in Hamburg on January 30, 2014. Protonet and many other start-ups in the country offer data security "made in Germany" after former U.S. National Security Agency contractor Edward Snowden alleged the NSA is engaged in industrial espionage and put software in almost 100,000 computers around the world. Picture taken January 30. TO GO WITH STORY DEUTSCHLAND-STARTUPS-NSA/ REUTERS/Fabian Bimmer (GERMANY - Tags: SCIENCE TECHNOLOGY BUSINESS TELECOMS)

Employees sit at their desks behind Orange Protonet servers at the headquarter of German company Protonet in Hamburg, January 30, 2014. Protonet and many other start-ups in the country offer data security "made in Germany" after former U.S. National Security Agency contractor Edward Snowden alleged the NSA is engaged in industrial espionage and put software in almost 100,000 computers around the world. Picture taken January 30. TO GO WITH STORY DEUTSCHLAND-STARTUPS-NSA/ REUTERS/Fabian Bimmer (GERMANY - Tags: SCIENCE TECHNOLOGY BUSINESS TELECOMS)

Hewlett-Packard ProLiant commercial data servers destined for cloud computing are assembled by workers at a company manufacturing facility in Houston November 19, 2013. REUTERS/Donna Carson (UNITED STATES - Tags: BUSINESS SCIENCE TECHNOLOGY)

Hewlett-Packard ProLiant commercial data servers destined for cloud computing are assembled by workers at a company manufacturing facility in Houston November 19, 2013. REUTERS/Donna Carson (UNITED STATES - Tags: BUSINESS SCIENCE TECHNOLOGY)

Hewlett-Packard ProLiant commercial data servers destined for cloud computing are assembled by workers at a company manufacturing facility in Houston November 19, 2013. REUTERS/Donna Carson (UNITED STATES - Tags: BUSINESS SCIENCE TECHNOLOGY)

Hewlett-Packard ProLiant commercial data servers destined for cloud computing are assembled by workers at a company manufacturing facility in Houston November 19, 2013. REUTERS/Donna Carson (UNITED STATES - Tags: BUSINESS SCIENCE TECHNOLOGY)

Hewlett-Packard ProLiant commercial data servers destined for cloud computing are assembled by workers at a company manufacturing facility in Houston November 19, 2013. REUTERS/Donna Carson (UNITED STATES - Tags: BUSINESS SCIENCE TECHNOLOGY)

Hewlett-Packard ProLiant commercial data servers destined for cloud computing are assembled by workers at a company manufacturing facility in Houston November 19, 2013. REUTERS/Donna Carson (UNITED STATES - Tags: BUSINESS SCIENCE TECHNOLOGY)

People stand under a sign showing the Lenovo company at a computer market in Shanghai January 21, 2014. China's Lenovo Group Ltd has resumed talks to buy International Business Machines Corp's (IBM) low-end server unit, a source familiar with the matter said - a purchase that would bolster its efforts to diversify beyond a shrinking PC market. REUTERS/Aly Song (CHINA - Tags: BUSINESS SCIENCE TECHNOLOGY)

Didier Bellens, chief executive officer of Belgium's telecom operator Belgacom attends a news conference at Belgacom headquarters in Brussels September 16, 2013. Belgium said on Monday it was investigating suspected foreign state espionage against its main telecoms company, which is the top carrier of voice traffic in Africa and the Middle East, and a newspaper pointed the finger at the United States. Federal prosecutors said in a statement that the former state telecoms monopoly Belgacom had filed a complaint in July about the hacking of several servers and computers. REUTERS/Yves Herman (BELGIUM - Tags: POLITICS BUSINESS TELECOMS CRIME LAW)

A woman leaves Belgium's telecom operator Belgacom headquarters in Brussels September 16, 2013. Belgium said on Monday it was investigating uspected foreign state espionage against its main telecoms company, which is the top carrier of voice traffic in Africa and the Middle East, and a newspaper pointed the finger at the United States. Federal prosecutors said in a statement that the former state telecoms monopoly Belgacom had filed a complaint in July about the hacking of several servers and computers. REUTERS/Yves Herman (BELGIUM - Tags: POLITICS BUSINESS TELECOMS CRIME LAW)

A logo of Belgium's telecom operator Belgacom is seen at an entrance of Belgacom headquarters in Brussels September 16, 2013. Belgium said on Monday it was investigating suspected foreign state espionage against its main telecoms company, which is the top carrier of voice traffic in Africa and the Middle East, and a newspaper pointed the finger at the United States. Federal prosecutors said in a statement that the former state telecoms monopoly Belgacom had filed a complaint in July about the hacking of several servers and computers. REUTERS/Yves Herman (BELGIUM - Tags: POLITICS BUSINESS TELECOMS CRIME LAW LOGO)

Belgian Minister for Public Enterprises and Development Cooperation Jean-Pascal Labille (L) and Didier Bellens, chief executive officer of Belgium's telecom operator Belgacom hold a joint news conference at Belgacom headquarters in Brussels September 16, 2013. Belgium said on Monday it was investigating suspected foreign state espionage against its main telecoms company, which is the top carrier of voice traffic in Africa and the Middle East, and a newspaper pointed the finger at the United States. Federal prosecutors said in a statement that the former state telecoms monopoly Belgacom had filed a complaint in July about the hacking of several servers and computers. REUTERS/Yves Herman (BELGIUM - Tags: POLITICS BUSINESS TELECOMS CRIME LAW)

Belgian Minister for Public Enterprises and Development Cooperation Jean-Pascal Labille (L) and Didier Bellens, chief executive officer of Belgium's telecom operator Belgacom (R) hold a joint news conference at Belgacom headquarters in Brussels September 16, 2013. Belgium said on Monday it was investigating suspected foreign state espionage against its main telecoms company, which is the top carrier of voice traffic in Africa and the Middle East, and a newspaper pointed the finger at the United States. Federal prosecutors said in a statement that the former state telecoms monopoly Belgacom had filed a complaint in July about the hacking of several servers and computers. REUTERS/Yves Herman (BELGIUM - Tags: POLITICS BUSINESS TELECOMS CRIME LAW)

Belgian Minister for Public Enterprises and Development Cooperation Jean-Pascal Labille (L) and Didier Bellens, chief executive officer of Belgium's telecom operator Belgacom (R) hold a joint news conference at Belgacom headquarters in Brussels September 16, 2013. Belgium said on Monday it was investigating suspected foreign state espionage against its main telecoms company, which is the top carrier of voice traffic in Africa and the Middle East, and a newspaper pointed the finger at the United States. Federal prosecutors said in a statement that the former state telecoms monopoly Belgacom had filed a complaint in July about the hacking of several servers and computers. REUTERS/Yves Herman (BELGIUM - Tags: POLITICS BUSINESS TELECOMS CRIME LAW)

Belgian Minister for Public Enterprises and Development Cooperation Jean-Pascal Labille (L) and Didier Bellens, chief executive officer of Belgium's telecom operator Belgacom, hold a joint news conference at Belgacom headquarters in Brussels September 16, 2013. Belgium said on Monday it was investigating suspected foreign state espionage against its main telecoms company, which is the top carrier of voice traffic in Africa and the Middle East, and a newspaper pointed the finger at the United States. Federal prosecutors said in a statement that the former state telecoms monopoly Belgacom had filed a complaint in July about the hacking of several servers and computers. REUTERS/Yves Herman (BELGIUM - Tags: POLITICS BUSINESS TELECOMS CRIME LAW)

Belgian Minister for Public Enterprises and Development Cooperation Jean-Pascal Labille (L) talks with of Didier Bellens, chief executive officer of Belgium's telecom operator Belgacom (R) after a news conference at Belgacom headquarters in Brussels September 16, 2013. Belgium said on Monday it was investigating suspected foreign state espionage against its main telecoms company, which is the top carrier of voice traffic in Africa and the Middle East, and a newspaper pointed the finger at the United States. Federal prosecutors said in a statement that the former state telecoms monopoly Belgacom had filed a complaint in July about the hacking of several servers and computers. REUTERS/Yves Herman (BELGIUM - Tags: POLITICS BUSINESS TELECOMS CRIME LAW)

Belgian Minister for Public Enterprises and Development Cooperation Jean-Pascal Labille (L) talks with of Didier Bellens, chief executive officer of Belgium's telecom operator Belgacom (R) after a news conference at Belgacom headquarters in Brussels September 16, 2013. Belgium said on Monday it was investigating suspected foreign state espionage against its main telecoms company, which is the top carrier of voice traffic in Africa and the Middle East, and a newspaper pointed the finger at the United States. Federal prosecutors said in a statement that the former state telecoms monopoly Belgacom had filed a complaint in July about the hacking of several servers and computers. REUTERS/Yves Herman (BELGIUM - Tags: POLITICS BUSINESS TELECOMS CRIME LAW)

Belgian Minister for Public Enterprises and Development Cooperation Jean-Pascal Labille (L) talks with of Didier Bellens, chief executive officer of Belgium's telecom operator Belgacom (R) after a news conference at Belgacom headquarters in Brussels September 16, 2013. Belgium said on Monday it was investigating suspected foreign state espionage against its main telecoms company, which is the top carrier of voice traffic in Africa and the Middle East, and a newspaper pointed the finger at the United States. Federal prosecutors said in a statement that the former state telecoms monopoly Belgacom had filed a complaint in July about the hacking of several servers and computers. REUTERS/Yves Herman (BELGIUM - Tags: POLITICS BUSINESS TELECOMS CRIME LAW)

A reporter of the YTN news channel prepares to report live in front of the Cyber Terror Response Center of the Korean National Police Agency in Seoul March 21, 2013. A hacking attack on Wednesday hit the network servers of television broadcasters YTN, MBC and KBS as well as two major commercial banks, Shinhan Bank and NongHyup Bank. About 32,000 computers at the organisations were affected, according to the South's state-run Korea Internet Security Agency, adding it would take up to five days to fully restore their functions. REUTERS/Lee Jae-Won (SOUTH KOREA - Tags: SCIENCE TECHNOLOGY CRIME LAW MEDIA BUSINESS POLITICS)