Exclusive: U.S. tried Stuxnet-style campaign against North Korea but failed - sources

US Cyber-Attack FAIL on North Korea

The United States tried to deploy a version of the Stuxnet computer virus to attack North Korea's nuclear weapons program five years ago but ultimately failed, according to people familiar with the covert campaign.

The operation began in tandem with the now-famous Stuxnet attack that sabotaged Iran's nuclear program in 2009 and 2010 by destroying a thousand or more centrifuges that were enriching uranium. Reuters and others have reported that the Iran attack was a joint effort by U.S. and Israeli forces.

According to one U.S. intelligence source, Stuxnet's developers produced a related virus that would be activated when it encountered Korean-language settings on an infected machine.

But U.S. agents could not access the core machines that ran Pyongyang's nuclear weapons program, said another source, a former high-ranking intelligence official who was briefed on the program.

53 PHOTOS
Kim Jong Un through the years
See Gallery
Exclusive: U.S. tried Stuxnet-style campaign against North Korea but failed - sources
This undated picture released by North Korea's official Korean Central News Agency on December 12, 2015 shows North Korean leader Kim Jong-Un (C) inspecting the newly renovated May 9 catfish farm at an undisclosed location in North Korea. REPUBLIC KOREA OUT -- AFP PHOTO / KCNA VIA KNS THIS PICTURE WAS MADE AVAILABLE BY A THIRD PARTY. AFP CAN NOT INDEPENDENTLY VERIFY THE AUTHENTICITY, LOCATION, DATE AND CONTENT OF THIS IMAGE. THIS IS DISTRIBUTED EXACTLY AS RECEIVED BY AFP. ---EDITORS NOTE--- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT 'AFP PHOTO / KCNA VIA KNS' - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS / AFP / KCNA / KNS (Photo credit should read KNS/AFP/Getty Images)
This undated picture released by North Korea's official Korean Central News Agency on December 12, 2015 shows North Korean leader Kim Jong-Un (C) inspecting the newly renovated May 9 catfish farm at an undisclosed location in North Korea. REPUBLIC KOREA OUT -- AFP PHOTO / KCNA VIA KNS THIS PICTURE WAS MADE AVAILABLE BY A THIRD PARTY. AFP CAN NOT INDEPENDENTLY VERIFY THE AUTHENTICITY, LOCATION, DATE AND CONTENT OF THIS IMAGE. THIS IS DISTRIBUTED EXACTLY AS RECEIVED BY AFP. ---EDITORS NOTE--- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT 'AFP PHOTO / KCNA VIA KNS' - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS / AFP / KCNA / KNS (Photo credit should read KNS/AFP/Getty Images)
This undated picture released by North Korea's official Korean Central News Agency on December 12, 2015 shows North Korean leader Kim Jong-Un (C) inspecting the newly renovated May 9 catfish farm at an undisclosed location in North Korea. REPUBLIC KOREA OUT -- AFP PHOTO / KCNA VIA KNS THIS PICTURE WAS MADE AVAILABLE BY A THIRD PARTY. AFP CAN NOT INDEPENDENTLY VERIFY THE AUTHENTICITY, LOCATION, DATE AND CONTENT OF THIS IMAGE. THIS IS DISTRIBUTED EXACTLY AS RECEIVED BY AFP. ---EDITORS NOTE--- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT 'AFP PHOTO / KCNA VIA KNS' - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS / AFP / KCNA / KNS (Photo credit should read KNS/AFP/Getty Images)
Travellers walk past a television screen showing North Korean leader Kim Jong-Un's New Year speech, at a railroad station in Seoul on January 1, 2015. North Korean leader Kim Jong-Un said he was open to the 'highest-level' talks with South Korea as he called for an improvement in strained cross-border relations. AFP PHOTO / JUNG YEON-JE (Photo credit should read JUNG YEON-JE/AFP/Getty Images)
KIM JONG-UN Leader of North Korea at plenary meeting of the central committee of the Worker's Party in Pyongyang in March 2013
North Korean leader Kim Jong Un meets with U.S. Secretary of State Mike Pompeo in this May 9, 2018 photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang May 10, 2018. KCNA / via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT.
North Korean leader Kim Jong Un (inside a vehicle) bids farewell to South Korean President Moon Jae-in as he leaves after a farewell ceremony at the truce village of Panmunjom inside the demilitarized zone separating the two Koreas, South Korea, April 27, 2018. Korea Summit Press Pool/Pool via Reuters TPX IMAGES OF THE DAY
North Korean leader Kim Jong Un makes a speech during a visit to Dalian, China in this undated photo released on May 9, 2018 by North Korea's Korean Central News Agency (KCNA). KCNA/via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT. NO COMMERCIAL OR EDITORIAL SALES IN SOUTH KOREA.
North Korean leader Kim Jong Un and his wife Ri Sol Ju walk together at the truce village of Panmunjom inside the demilitarized zone separating the two Koreas, South Korea, April 27, 2018. Korea Summit Press Pool/Pool via Reuters
North Korean leader Kim Jong Un and South Korean President Moon Jae-in deliver a statement at the truce village of Panmunjom inside the demilitarized zone separating the two Koreas, South Korea, April 27, 2018. Korea Summit Press Pool/Pool via Reuters
North Korean leader Kim Jong Un attends a meeting with South Korean President Moon Jae-in at the Peace House at the truce village of Panmunjom inside the demilitarized zone separating the two Koreas, South Korea, April 27, 2018. Korea Summit Press Pool/Pool via Reuters
North Korean leader Kim Jong Un speaks during the Third Plenary Meeting of the Seventh Central Committee of the Workers' Party of Korea (WPK), in this photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on April 20, 2018. KCNA/via Reuters ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT.
North Korean leader Kim Jong Un and his wife Ri Sol Ju watch South Korean K-pop singers perform in a concert under the title "Spring is Coming" at the East Pyongyang Grand Theatre on April 1 in North Korea in this photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang April 2, 2018. KCNA/via Reuters ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT. TPX IMAGES OF THE DAY
North Korean leader Kim Jong Un meets members of the high-level delegation of the Democratic People's Republic of Korea which visited South Korea to attend the opening ceremony of the 23rd Winter Olympics in this undated photo released by North Korea's Korean Central News Agency (KCNA) February 13, 2018. KCNA/via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT. NO COMMERCIAL OR EDITORIAL SALES IN SOUTH KOREA
North Korean leader Kim Jong Un attends a grand military parade celebrating the 70th founding anniversary of the Korean People's Army at the Kim Il Sung Square in Pyongyang, in this photo released by North Korea's Korean Central News Agency (KCNA) February 9 2018. KCNA/via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT.
North Korea's leader Kim Jong Un speaks during a New Year's Day speech in this photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on January 1, 2018. KCNA / via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT.
North Korean leader Kim Jong Un visits the newly-remodeled Pyongyang Teacher Training College, in this photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on January 17, 2018. KCNA/via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT.
North Korean leader Kim Jong Un reacts as people applaud during his visit to the newly-remodeled Pyongyang Teacher Training College, in this photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on January 17, 2018. KCNA/via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT.
North Korean leader Kim Jong-un gives opening remarks at the 5th Conference of Cell Chairpersons of the Workers' Party of Korea (WPK), in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on December 22,2017. KCNA/via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. SOUTH KOREA OUT. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS
North Korean leader Kim Jong Un gives field guidance to various units in Samjiyon County, in this photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang December 9, 2017. KCNA/via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. SOUTH KOREA OUT. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS
FILE PHOTO: North Korean leader Kim Jong Un reacts with Ri Pyong Chol (L) in this undated photo released by North Korea's Korean Central News Agency (KCNA) on May 15, 2017. To match Insight NORTHKOREA-KIMJONGUN/ KCNA/via REUTERS/File Photo ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT.
North Korea's leader Kim Jong Un is seen as the newly developed intercontinental ballistic rocket Hwasong-15's test was successfully launched, in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang November 30, 2017. REUTERS/KCNA ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. SOUTH KOREA OUT. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS TPX IMAGES OF THE DAY
North Korean leader Kim Jong Un inspects the Sungri Motor Plant, in this undated picture provided by KCNA in Pyongyang on November 21, 2017. KCNA via Reuters ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. SOUTH KOREA OUT. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS.
North Korean leader Kim Jong-Un inspects the January 18 General Machine Plant in Pyongyang, North Korea in this undated photo released by North Korea's Korean Central News Agency (KCNA) on August 10, 2016. KCNA/via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. NO THIRD PARTY SALES. SOUTH KOREA OUT. NO COMMERCIAL OR EDITORIAL SALES IN SOUTH KOREA.
North Korea's leader Kim Jong Un visits the Mangyongdae Revolutionary Academy on its 70th anniversary, in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang October 13, 2017. REUTERS/KCNA ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT. NO COMMERCIAL OR EDITORIAL SALES IN SOUTH KOREA. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS.
North Korean leader Kim Jong Un gives field guidance during a visit to a fruit orchard in Kwail county, South Hwanghae province in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang September 21, 2017. KCNA via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT. TPX IMAGES OF THE DAY
North Korea's leader Kim Jong Un makes a statement regarding U.S. President Donald Trump's speech at the U.N. general assembly, in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang September 22, 2017. KCNA via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT. TPX IMAGES OF THE DAY
North Korean leader Kim Jong Un visits a Farm No. 1116 of KPA Unit 810 in this September 29, 2017 photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang. KCNA/via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT.
North Korean leader Kim Jong Un gives field guidance during a visit to a fruit orchard in Kwail county, South Hwanghae province in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang September 21, 2017. KCNA via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT.
North Korean leader Kim Jong Un guides the launch of a Hwasong-12 missile in this undated photo released by North Korea's Korean Central News Agency (KCNA) on September 16, 2017. KCNA via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT. TPX IMAGES OF THE DAY
REFILE - ADDITIONAL INFORMATION North Korean leader Kim Jong Un provides guidance with Ri Hong Sop (2nd L) and Hong Sung Mu (R) on a nuclear weapons program in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang September 3, 2017. KCNA via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT. NO COMMERCIAL OR EDITORIAL SALES IN SOUTH KOREA. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS.
FILE PHOTO: North Korean leader Kim Jong Un participates in a meeting with the Presidium of the Political Bureau of the Central Committee of the Workers�Party of Korea in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang September 4, 2017. KCNA via REUTERS/File Photo ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT. NO COMMERCIAL OR EDITORIAL SALES IN SOUTH KOREA. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS.
North Korean leader Kim Jong Un reacts with scientists and technicians of the DPRK Academy of Defence Science after the test-launch of the intercontinental ballistic missile Hwasong-14 in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang July, 5, 2017. KCNA/via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT.
FILE PHOTO - North Korean leader Kim Jong Un reacts during the long-range strategic ballistic rocket Hwasong-12 (Mars-12) test launch in this undated photo released by North Korea's Korean Central News Agency (KCNA) on May 15, 2017. KCNA via REUTERS/File Photo REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT.
FILE PHOTO: North Korean leader Kim Jong-Un speaks during the first congress of the country's ruling Workers' Party in 36 years in Pyongyang, in this handout photo provided by KCNA on May 6, 2016. KCNA/via Reuters/File Photo ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. FOR EDITORIAL USE ONLY. NO THIRD PARTY SALES. SOUTH KOREA OUT. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS
North Korean leader Kim Jong Un reacts during the 8th Congress of the Korean Children's Union (KCU) at the April 25 House of Culture in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang June 7, 2017. REUTERS/KCNA ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT. NO COMMERCIAL OR EDITORIAL SALES IN SOUTH KOREA. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS.
North Korean leader Kim Jong Un reacts during a ballistic rocket test-fire through a precision control guidance system in this undated photo released by North Korea's Korean Central News Agency (KCNA) May 30, 2017. KCNA/via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. EDITORIAL USE ONLY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT.
North Korean leader Kim Jong Un waves to people attending a military parade marking the 105th birth anniversary of country's founding father, Kim Il Sung in Pyongyang, April 15, 2017. REUTERS/Damir Sagolj TPX IMAGES OF THE DAY
North Korean Leader Kim Jong Un gives field guidance to the Pyongyang mushroom factory in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on April 8, 2017. KCNA/via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. EDITORIAL USE ONLY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. SOUTH KOREA OUT. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. TPX IMAGES OF THE DAY
North Korean leader Kim Jong Un gives field guidance to the remodeled Korean Revolution Museum in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on March 28, 2017. KCNA/via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT. NO COMMERCIAL OR EDITORIAL SALES IN SOUTH KOREA.
North Korean leader Kim Jong Un watches a performance given with splendor at the People's Theatre on Wednesday to mark the 70th anniversary of the founding of the State Merited Chorus in this photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on February 23, 2017. KCNA/via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT. NO COMMERCIAL OR EDITORIAL SALES IN SOUTH KOREA.
North Korean leader Kim Jong Un inspects the Headquarters of Large Combined Unit 966 of the Korean People's Army (KPA) in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on March 1, 2017. KCNA/via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT. NO COMMERCIAL OR EDITORIAL SALES IN SOUTH KOREA.
North Korean leader Kim Jong Un visits the bier of Kang Ki Sop, alternate member of the Central Committee of the Workers' Party of Korea, deputy to the Supreme People's Assembly of the DPRK and general director of the General Administration of Civil Aviation, in this undated photo released by North Korea's Korean Central News Agency (KCNA) January 23, 2017. KCNA via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. FOR EDITORIAL USE ONLY. NO THIRD PARTY SALES. SOUTH KOREA OUT.
North Korean leader Kim Jong Un visits a newly built Pyongyang bag factory in this undated photo released by North Korea's Korean Central News Agency (KCNA) January 5, 2017. REUTERS/KCNA ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. FOR EDITORIAL USE ONLY. NO THIRD PARTY SALES. SOUTH KOREA OUT.
North Korean leader Kim Jong Un watches the Masikryong ski competition-2016 in this undated photo released by North Korea's Korean Central News Agency (KCNA) December 20, 2016. KCNA via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. EDITORIAL USE ONLY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT.
North Korean leader Kim Jong Un guides the combat drill of the service personnel of the special operation battalion of KPA Unit 525 in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on December 11, 2016. KCNA via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. EDITORIAL USE ONLY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT.
North Korean leader Kim Jong Un provides field guidance to the Mangyongdae Revolutionary Site Souvenir Factory in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on October 7, 2016. KCNA/ via REUTERS ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. FOR EDITORIAL USE ONLY. NO THIRD PARTY SALES. SOUTH KOREA OUT.
North Korean leader Kim Jong Un inspects a special operation battalion under KPA Unit 525 in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang November 4, 2016. KCNA via REUTERS ATTENTION EDITORS - THIS IMAGE WAS PROVIDED BY A THIRD PARTY. EDITORIAL USE ONLY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE. NO THIRD PARTY SALES. SOUTH KOREA OUT. TPX IMAGES OF THE DAY
North Korean leader Kim Jung-un visits the May 27th and January 8th fishery stations, which made an unprecedented catch of fishes, in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang on November 17, 2016. REUTERS/KCNA ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. FOR EDITORIAL USE ONLY. NO THIRD PARTY SALES. SOUTH KOREA OUT. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS.
North Korean leader Kim Jong Un meets Salvador Antonio Valdes Mesa, member of the Political Bureau of the Central Committee of the Communist Party of Cuba (CPC) and vice-president of the Council of State of Cuba, and his party on a visit, in this undated photo released by North Korea's Korean Central News Agency (KCNA) July 1, 2016. REUTERS/KCNA/File PhotoATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. FOR EDITORIAL USE ONLY. NO THIRD PARTY SALES. SOUTH KOREA OUT. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS.
North Korean leader Kim Jong Un waves to the crowd as he presides over a mass rally and parade in the capital's main ceremonial square, in Pyongyang, North Korea, May 10, 2016. North Korea's parliament awarded Kim Jong Un a new post on June 29, 2016, the chairman of the state affairs committee, a body that appears to be newly formed and whose function was not immediately clear, North's state television said. REUTERS/Damir Sagolj/File Photo
North Korean leader Kim Jong Un visits the Kwisong Saltern to learn about the salt production from underground ultra-saline water by the KPA in this undated photo released by North Korea's Korean Central News Agency (KCNA) on May 24, 2016. REUTERS/KCNA ATTENTION EDITORS - THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. NO THIRD PARTY SALES. NOT FOR USE BY REUTERS THIRD PARTY DISTRIBUTORS. SOUTH KOREA OUT. NO COMMERCIAL OR EDITORIAL SALES IN SOUTH KOREA. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS.
North Korean leader Kim Jong Un waves to the crowd as he presides over a mass rally and parade in the capital's main ceremonial square, a day after the ruling party wrapped up its first congress in 36 years by elevating him to party chairman, in Pyongyang, North Korea, May 10, 2016. REUTERS/Damir Sagolj
HIDE CAPTION
SHOW CAPTION
of
SEE ALL
BACK TO SLIDE

The official said the National Security Agency-led campaign was stymied by North Korea's utter secrecy, as well as the extreme isolation of its communications systems. A third source, also previously with U.S. intelligence, said he had heard about the failed cyber attack but did not know details.

North Korea has some of the most isolated communications networks in the world. Just owning a computer requires police permission, and the open Internet is unknown except to a tiny elite. The country has one main conduit for Internet connections to the outside world, through China.

In contrast, Iranians surfed the Net broadly and had interactions with companies from around the globe.

A spokeswoman for the NSA declined to comment for this story. The spy agency has previously declined to comment on the Stuxnet attack against Iran.

The United States has launched many cyber espionage campaigns, but North Korea is only the second country, after Iran, that the NSA is now known to have targeted with software designed to destroy equipment.

Washington has long expressed concerns about Pyongyang's nuclear program, which it says breaches international agreements. North Korea has been hit with sanctions because of its nuclear and missile tests, moves that Pyongyang sees as an attack on its sovereign right to defend itself.

U.S. Secretary of State John Kerry said last week that Washington and Beijing were discussing imposing further sanctions on North Korea, which he said was "not even close" to taking steps to end its nuclear program.

SIEMENS SOFTWARE

Experts in nuclear programs said there are similarities between North Korea and Iran's operations, and the two countries continue to collaborate on military technology.

Both countries use a system with P-2 centrifuges, obtained by Pakistani nuclear scientist A.Q. Khan, who is regarded as the father of Islamabad's nuclear bomb, they said.

Like Iran, North Korea probably directs its centrifuges with control software developed by Siemens AG that runs on Microsoft Corp's Windows operating system, the experts said. Stuxnet took advantage of vulnerabilities in both the Siemens and Microsoft programs.

Because of the overlap between North Korea and Iran's nuclear programs, the NSA would not have had to tinker much with Stuxnet to make it capable of destroying centrifuges inNorth Korea, if it could be deployed there.

Despite modest differences between the programs, "Stuxnet can deal with both of them. But you still need to get it in," said Olli Heinonen, senior fellow at Harvard University's Belfer Center for Science and International Affairs and former deputy director general of the International Atomic Energy Agency.

NSA Director Keith Alexander said North Korea's strict limitations on Internet access and human travel make it one of a few nations "who can race out and do damage with relative impunity" since reprisals in cyberspace are so challenging.

When asked about Stuxnet, Alexander said he could not comment on any offensive actions taken during his time at the spy agency.

David Albright, founder of the Institute for Science and International Security and an authority on North Korea's nuclear program, said U.S. cyber agents probably tried to get toNorth Korea by compromising technology suppliers from Iran, Pakistan or China.

"There was likely an attempt" to sabotage the North Korean program with software, said Albright, who has frequently written and testified on the country's nuclear ambitions.

OLYMPIC GAMES

The Stuxnet campaign against Iran, code-named Olympic Games, was discovered in 2010. It remains unclear how the virus was introduced to the Iranian nuclear facility in Natanz, which was not connected to the Internet.

According to cybersecurity experts, Stuxnet was found inside industrial companies in Iranthat were tied to the nuclear effort. As for how Stuxnet got there, a leading theory is that it was deposited by a sophisticated espionage program developed by a team closely allied to Stuxnet's authors, dubbed the Equation Group by researchers at Kaspersky Lab.

The U.S. effort got that far in North Korea as well. Though no versions of Stuxnet have been reported as being discovered in local computers, Kaspersky Lab analyst Costin Raiu said that a piece of software related to Stuxnet had turned up in North Korea.

Kaspersky had previously reported that the software, digitally signed with one of the same stolen certificates that had been used to install Stuxnet, had been submitted to malware analysis site VirusTotal from an electronic address in China. But Raiu told Reuters his contacts had assured him that it originated in North Korea, where it infected a computer in March or April 2010.

Some experts said that even if a Stuxnet attack against North Korea had succeeded, it might not have had that big an impact on its nuclear weapons program. Iran's nuclear sites were well known, whereas North Korea probably has at least one other facility beyond the known Yongbyon nuclear complex, former officials and inspectors said.

In addition, North Korea likely has plutonium, which does not require a cumbersome enrichment process depending on the cascading centrifuges that were a fat target for Stuxnet, they said.

Jim Lewis, an advisor to the U.S. government on cybersecurity issues and a senior fellow at the Center for Strategic and International Studies, said there are limitations to cyber offense.

A cyber attack "is not something you can release and be sure of the results," Lewis said.

(Editing by Tiffany Wu)

Read Full Story