As of Monday, ethical hackers had returned $36.2 million to cross-chain interoperability protocol Nomad’s recovery wallet through 41 wallet addresses, according to an official tweet released Monday.

The vast majority of returned funds are in stablecoins USD Coin ( USDC ), Tether ( USDT ) and altcoin Frax.

The security of cross-chain bridges has become a hidden danger in the crypto industry. The hack occurred just four months after Nomad closed a $22.4 million seed round in April, with more than $190 million worth of tokens stolen in less than three hours.