Japanese police and U.S. agencies said the attack was "affiliated" with TraderTraitor, which is characterized by social engineering.
What to know:
- The theft of more than 4,500 bitcoin from Japanese crypto exchange DMM was perpetrated by hackers linked to North Korea, the FBI, Department of Defense and Japan's police force said.
- The attack targeted an employee at crypto wallet company Ginco, giving the hackers access to its communications system.
- Later, they used that access to intercept a legitimate transaction from a DMM employee, leading to the loss.
The $308 million hack of Japanese crypto exchange DMM in May was the work of North Korean hackers, the U.S. and Japanese law enforcement agencies said Monday.
The theft of 4,502.9 bitcoin (BTC), which is forcing the exchange to close, was "affiliated" with a group known as TraderTraitor, the FBI said in a statement with the Department of Defense Cyber Crime Center and National Police Agency of Japan.
Hackers linked to North Korea dominated crypto crime this year, Chainalysis said in its annual report on the subject. The country, whose official name is the Democratic People's Republic of Korea (DPRK), is tied to more than half of the crypto value stolen in 2024. Its operatives are responsible for the theft of $1.34 billion across 47 incidents, more than double the $660 million (a figure revised down from an initial estimate) taken last year.
TraderTraitor, also known as Jade Sleet, UNC4899 and Slow Pisces, generally works by targeted social engineering, according to the statement. In this case, malicious code was inserted into a Python script used in a fictitious pre-employment test and sent by an operative posing as a recruiter on LinkedIn to a candidate who worked at an outside enterprise, crypto wallet company Ginco.
The victim copied the code to their personal Github page, giving TraderTraitor access to session cookie information that allowed it access to Ginco's communications system. Months later, it probably used the access to intercept a legitimate transaction request by a DMM employee, leading to the theft, the agencies said.