Over the weekend, hackers stole over $290 million in cryptocurrency from Kelp DAO, a platform that allows users to earn yields on idle crypto investments. By Monday, LayerZero, one of the affected projects, had accused North Korea of carrying out this heist.

The hack is now the largest cyber theft of the year so far, following an earlier hack at crypto exchange Drift in April that netted hackers around $285 million. Per its post on X, LayerZero said the hackers exploited Kelp DAO via its LayerZero bridge, which allows different blockchains to send instructions to each other.

The company cited “preliminary indicators” pointing to North Korea as the culprit, in particular its hacking group known as TraderTraitor. In response, Kelp DAO denied blame for the theft.

Over the past few years, North Korean hackers have become highly successful at stealing crypto. Last year, they stole more than $2 billion in cryptocurrency. Overall, since 2017, the total amount of stolen crypto by North Korea is said to be around $6 billion.