UK-based cryptocurrency exchange EXMO informed customers on Monday that it discovered large withdrawals from its hot wallets.
Founded in 2013, the exchange claims more than 27,000 active traders at the moment.
While it did not reveal the exact amount of stolen funds, the exchange did say it observed transfers out of its Bitcoin, Ripple, Zcash, Tether, Ethereum Classic, and Ethereum hot wallets.
“We are still investigating the incident, but as of now, the security audit report showed that some amounts of BTC, XRP, ZEC, USDT, ETC and ETH in EXMO’s hot wallets were transferred out of the exchange,” EXMO announced.
The company said it immediately re-deployed hot wallets, but admitted that the affected ones comprise approximately 5% of the total assets.
The assets stored in cold wallets were not affected by the security incident, EXMO said, adding that all funds stolen in the attack will be covered by the exchange.
The Block has calculated that EXMO lost roughly $10.5 million worth of funds as a result of the incident.
EXMO has published a list of the wallets the attackers transferred funds to, asking other exchanges to block transactions to and from them.
“We kindly ask all the services and exchanges to block all the accounts that are connected to these wallets. Currently, we are locating the reason for the incident and will keep this list updated,” EXMO noted in a blog post.
The company has already informed law enforcement of the security incident and suspended withdrawals for the time being.
“While the investigation is still in progress, we want to assure you that we have taken all the necessary measures for your safety. Funds depositing and withdrawal are still suspended. But don’t worry. It’s just a temporary measure,” the exchange said in a tweet today.
Related: $150 Million Stolen From Singaporean Crypto-Exchange KuCoin
Related: Hackers Steal $5.4 Million From Crypto Exchange Eterbase
Related: Spooks Called in as Cyberattacks Again Halt NZ Stock Exchange