With bitcoin reaching record heights recently, the cryptocurrency has become the target of many cyber criminals. Bithumb, the fourth largest bitcoin exchange in the world and the largest in South Korea, suffered a hack that caused billions of won to vaporize from compromised accounts.
The exchange has a 75.7 percent share of the South Korean bitcoin market, with a daily trading volume of over 13,000 bitcoins. It is also the world’s largest ethereum market and accounts for around 44 percent of South Korea’s ether trading.
Hackers unleashed a cyber-attack last week that managed to grab the personal information of 31,800 members, around three percent of the website’s user base, including names, phone numbers and e-mail addresses. Afterward, they proceeded with a phishing campaign, calling up users one at a time, posing as representatives of Bithumb.
The company admitted that it was hacked, but maintained that the hackers did not obtain direct access to funds stored on the exchange. However, the phishing effort seems successful as many customers are finding their digital wallets empty. More than 100 Bithumb users have filed a complaint with the National Police Agency's cyber crime report center. The company claims that the breach occurred on an employee’s computer and not on the exchange’s internal network.
"The employee PC, not the head office server, was hacked. Personal information such as mobile phone and email address of some users were leaked. However, some customers were found to have been stolen from because of the disposable password used in electronic financial transactions.”
According to a notice on Bithumb’s website, the company will compensate all members whose information was compromised with up to 100,000 won ($870) per person. Users who had larger monetary losses will be compensated further as soon as the amount is confirmed.