Mercado Bitcoin, Brazil’s largest crypto exchange, has suspended deposits and withdrawals after a security incident in one of its systems early on Monday, 2 November.
In a statement on X, the exchange said the incident was “quickly contained” and described the suspension as “a preventive protection measure.” It said no customer money had been lost and no data had leaked.
Mercado Bitcoin had not given a date for deposits and withdrawals to resume at the time of writing, and said it would post regular updates on X.
Suspected $40 million taken
Blockchain security firm Hypernative flagged more than $40 million in suspicious transfers linked to the incident, based on a preliminary analysis across at least 10 blockchains, including Bitcoin, Ethereum, Solana and Tron.
Mercado Bitcoin had not confirmed the $40 million figure at the time of writing, and had not said how the attackers got in.
In a follow-up post, the exchange published the addresses the funds were sent to on EVM chains, Bitcoin, Solana, Stellar and Tron, so that others can track them.
Tether freezes USDT
Tether CEO Paolo Ardoino said on X that the stablecoin issuer “froze more than 4.5M USDT” related to the incident.
A freeze stops the stolen tokens from being moved, but it does not on its own return them to their owner.
A week of exchange hacks
The incident comes days after Binance lost an estimated $6.3 billion in the largest crypto theft on record. The FBI has attributed that attack to TraderTraitor, a group linked to North Korea. Binance has since reopened withdrawals and says it has covered about 95% of the affected assets.
Mercado Bitcoin has not linked its incident to the Binance hack, and had not said who was behind the attack at the time of writing.
What happens next
Customers will be watching for a date to resume withdrawals, confirmation of how much was taken, and whether Mercado Bitcoin sets out how it will cover any losses.
