The flags of Korea, the United States and Coupang hang at the New York Stock Exchange, March 11, 2021, when Coupang, the U.S.-headquartered holding firm of Coupang, began its trading. Yonhap

Coupang was slapped with a record fine of 624.7 billion won ($409 million) for a massive data breach involving more than 33 million users, marking the largest privacy penalty in Korea, a regulatory authority said Thursday.

The penalty is roughly equivalent to Coupang's operating profit of 721.1 billion won last year.

According to the Personal Information Protection Commission, it decided to impose the penalty on the e-commerce firm due to the unprecedented scale of the data leak and the gravity of the incident.

A joint government-civilian investigation — led by the Ministry of Science and ICT — revealed that a former Coupang employee hacked into the company’s system last year, leaking the personal data of 33.67 million customers.