Mercado Bitcoin halts deposits and withdrawals after security breach

Mercado Bitcoin suspended deposits and withdrawals on Monday after detecting a security incident in one of its systems in the early hours, the Brazilian crypto exchange said, days after Binance disclosed the largest crypto hack on record.

The exchange said in a statement on X that no customer funds were lost and no data leaked, and that the freeze was a precaution while internal teams investigate. In a second update it said it was working to "restore operations safely" and published the destination addresses identified in movements linked to the incident so the assets could be traced on-chain.

The breach lands days after Binance, the world's largest digital asset platform, reported that attackers drained more than $6bn from wallets across at least four blockchains. Mercado Bitcoin's decision to publish wallet addresses points to the tracing role exchanges now play in the aftermath of an attack.

The timing has sharpened concern about a run of attacks this year on crypto companies and the wider financial sector, and whether artificial intelligence is making hackers more efficient. Some security specialists believe North Korean hackers have added AI tools to their arsenal, particularly for reconnaissance and social engineering, according to Token Times.

Recent incidents have also hit the prediction market Polymarket, South Korean financial firms Mirae Asset Global Investments and Daishin Securities, and Japanese currency trading platform GMO Internet Group.