South Korean cryptocurrency exchange Gdac was hacked on Sunday and lost nearly $13 million, the company revealed on Monday.

The hackers took nearly $13 million worth of cryptocurrencies, or 23 percent of Gdac's total custodial assets, and transferred those assets from the exchange's hot wallet to an unidentified wallet.

The hackers stole nearly 61 Bitcoin (BTC), 350.5 Ether (ETH), 10 million wemix tokens (WEMIX) and 220,000 Teda tokens (USDT). The Gdac said it had informed the authorities about the hack and was working to recover the funds.

Over the past 15 to 18 months, cryptocurrency platforms have suffered a series of high-profile hacks. The biggest was Axie Infinity's Ronin Bridge, which was hacked for $625 million last year. On Sunday, decentralized finance protocol Sushi had $3.3 million stolen.