The largest bitcoin and ether exchange in South Korea by volume, Bithumb, was recently hacked. Monetary losses from compromised accounts have started to surface, and are quickly reaching into the billions of won.
With a reported 75.7% share of the South Korean bitcoin market volume, Bithumb is one of the five largest bitcoin exchanges in the world and hosts over 13,000 bitcoins worth of trading volume daily, or roughly 10 percent of the global bitcoin trade.
The exchange also hosts the world's largest ether market. While trade in the South Korean won currently makes up the fourth largest currency market for bitcoin, trailing the US dollar, Chinese yuan and Japanese yen, the won market is Ethereum’s largest. Bithumb accounts for around 44 percent of South Korean ether trading.
A cyber attack late last week resulted in the loss of billions of won from customers accounts, according to a major local newspaper, the Kyunghyang Shinmun. One victim alone claimed that "Bitcoins worth 10 million won” in his account “disappeared instantly.”
Hackers succeeded in grabbing the personal information of 31,800 Bithumb website users, including their names, mobile phone numbers and email addresses. The exchange claims that this number represents approximately three percent of customers.
The breach was discovered by Bithumb on June 29 and reported to the authorities on June 30. More than 100 Bithumb customers have since filed a complaint with the National Police Agency's cybercrime report center.
While admitting to being hacked on their website, Bithumb maintained that there was no direct access to funds stored on the exchange. Nonetheless, many customers are reporting their digital currency wallets being emptied. The exchange further claims that the breach was made to a personal computer belonging to an employee, and not the exchange’s internal network, servers nor digital currency wallets.