South Korea’s National Intelligence Service (NIS) recently informed the country’s parliament it believes North Korean hackers stole millions of dollars’ worth of cryptocurrency from its cryptocurrency exchanges last year.

According to local news outlet Kyodo News, while briefing the country’s lawmakers on cyberattacks, the agency revealed they were investigating whether North Korean hackers were behind last month’s attack on Japanese exchange CoinCheck that netted attackers $534 million.

Per the NIS, North Korean actors managed to steal “tens of billions of won” in cryptocurrencies from the country’s exchanges through attacks based on phishing emails sent to their users. Moreover, reports suggest the NIS secured evidence that North Korean hackers were behind last year’s attack on Bithumb, that saw 8 billion won (about $7.2 million) stolen, along with the personal information of over 30,000 users.

The agency also claims local exchange Coinus was attacked by the regime’s hackers. Reuters reports that South Korean parliament member Kim Byung-kee shed some light on the attack, stating:

“North Korea sent emails that could hack into cryptocurrency exchanges and their customers’ private information and stole (cryptocurrency) worth billions of won.”

Kim Byung-kee

Experts believe North Korea is going after cryptocurrencies in order to bypass sanctions imposed by the United Nations in September. The sanctions were implemented in response to North Korean missile tests and place strict embargoes on oil and textiles. Last year, South Korean government officials accused the country of attempting to trick 25 employees at four different exchanges through spear phishing attacks.

Kyodo News pointed out the popularity cryptocurrencies have in South Korea, as an estimated 3 million South Koreans are believed to have bought cryptocurrencies last year. In response to the popularity, the country enforced a real-name trading rule to stop anonymous trading accounts and enforce know your customer (KYC) regulations.

While South Korea is regulating cryptocurrency markets in the country, China’s crackdown seemingly has no end in sight. Recently, two major Chinese websites banned cryptocurrency-related ads from their platforms.