Latin America's largest crypto exchange, Mercado Bitcoin, suffers hacker attack, loses over $46 million, and halts withdrawals.

Mercado Bitcoin, Latin America's largest licensed crypto exchange, has suspended all deposits and withdrawals after a security breach drained more than $46 million in digital assets from its on-chain custody system. On-chain analytics firm Arkham, whose analyst Emmett Gallic is tracking the incident, reports that the attacker is sweeping the exchange's dormant historical deposit addresses and rapidly dumping stolen altcoins and memecoins on decentralized markets, with losses still climbing. The Brazil-based exchange says its security team contained the breach the same morning, that customers suffered no direct losses and no user data was leaked, and characterizes the withdrawal freeze as a precautionary measure while it works with Brazilian judicial and regulatory authorities on tracing the attack. Mercado Bitcoin has published the hacker's wallet addresses on-chain, asking platforms and node operators to help intercept the funds. The incident follows a period of intense exchange-targeting attacks, including a Binance alert that saw over $6 billion in short-term net outflows, with US law enforcement probing possible links to North Korea's "Trader Traitor" group and even ordering THORChain node operators to block tainted addresses. Watch for whether the exchange restores withdrawals, the final loss tally, and regulatory scrutiny of its key management for legacy deposit addresses.