On March 30 tweet, the crypto exchange Bithumb announced a temporary pause of its cryptocurrency withdrawals and deposits system.
On the tweet, the Bithumb revealed that at 10:15 (time zone unknown) on the 29th, they detected abnormal withdrawals through their system. Therefore, the exchange have “secured all the cryptocurrency from the detection time with a cold wallet and checked them by blocking deposit and withdrawal service.”
Based on the translated note, this was an “accident involving insiders” and Bithumb is investigating with security companies, the cyber police agency, and KISA. Users inspect that this could be because of Bithumb’s layoffs, which are up to 50% of its workforce.
According to unconfirmed information of crypto user Dovey Wan, more than 3 million EOS (around $12.5 million) has been moved at at Bithumb’s cold storage level. All the stolen funds so far belonged to the exchange itself, not users. As The Block Crypto reported, around 20 million Ripple (XRP) (equivalent to about $6.2 million) has also been stolen.
Soon after the hack, a Twitter user showed a stolen funds analysis which demonstrated the funds’ distribution to other exchanges and to some addresses. The exchange that received the most funds (662,000 EOS) is EXMO, followed by Houbi (263,000 EOS), Changelly (192,000 EOS), ChangeNOW (140,000 EOS), KuCoin (96,000 EOS) and others.
Related to this matter, Changelly has already announced that it has blocked 243,000 XRP ($76,000) and 114,000 EOS ($479,000) which are considered being transferred from Bithumb. There were total 8 transactions of XRP and 52 of EOS. All these related wallet addresses have been blacklisted after that.
In June 2018, Bithumb was hacked around $30 million in cryptocurrencies but only recovered $14 million of the stolen funds.