SEOUL: South Korea’s spy agency said North Korean hackers were behind attacks on cryptocurrency exchanges this year in which some 7.6 billion won ($6.99 million) worth of cryptocurrencies were stolen, a newspaper reported on Saturday.

Attacks also included the theft of cryptocurrencies from accounts at exchanges Yapizon, now called Youbit, and Coinis in April and September, it said.

Another cyber attack on about 10 cryptocurrency exchanges by North Korean hackers in October, using emails containing malware, was thwarted by the Korea Internet Security Agency (KISA), the newspaper reported.

The NIS found that the malware used in hacking the exchanges was made with the same method as malware used in hacking Sony Pictures and the central bank of Bangladesh in 2014 and 2016 respectively, the Chosun Ilbo reported.

The NIS also said emails used in the attacks used North Korean internet addresses, according to the Chosun Ilbo.

The NIS declined to comment. Representatives for KISA, Bitthumb, Youbit and Coinis could not be reached for comment.