Mercado Bitcoin Suspends Transfers After Cyberattack; Nearly $7 Million in Assets Frozen

Brazilian cryptocurrency exchange Mercado Bitcoin suspended deposits and withdrawals after detecting a security incident in one of its systems. Hypernative flagged more than $40 million in suspicious transfers across at least 10 blockchains, while Arkham grouped 36 addresses and reported that the attacker held approximately $46 million. These figures do not establish the exchange’s actual loss, which remains undisclosed. Mercado Bitcoin said it quickly contained the incident, customers suffered no losses, and no data leaked; it also published destination addresses to help track the funds.

A researcher estimated that nearly $7 million in assets linked to the incident had been frozen. Tether reported freezing more than 4.5 million USDT, with blacklist actions visible on Ethereum and Tron; onchain records also showed Circle freezing USDC on Polygon and Paxos freezing gold tokens on Ethereum. Researchers characterized the suspicious movements as ordinary transfers rather than a smart contract exploit, leaving the source of signing access and the affected internal system unresolved. Deposits and withdrawals remained suspended with no reopening time announced, and the exchange’s customer assurances did not clarify whether company-owned assets were stolen.