
Brazil’s largest crypto exchange Mercado Bitcoin halts withdrawals after reported $40M hack - Finbold
Brazil's largest cryptocurrency exchange Mercado Bitcoin has suspended deposits and withdrawals following a security incident reportedly involving more than $40 million in digital assets.
Blockchain security firm Hypernative first flagged the suspicious activity on November 2 after identifying transfers from wallets attributed to Mercado Bitcoin to newly created addresses across multiple blockchain networks. The firm estimated that more than $40 million worth of assets may have been affected.
Mercado Bitcoin later acknowledged the incident in an official update and said deposits and withdrawals had been temporarily suspended while its teams investigated the breach.
Identificamos e contivemos com rapidez um incidente de segurança em um de nossos sistemas nesta madrugada. Reforçamos que: • Não houve nenhum prejuízo aos clientes; • Não houve vazamento de dados. Como medida preventiva de proteção, depósitos e saques…
Customer Funds Protected
The exchange has maintained that customer funds remain safe, while the exact value of the assets lost has not yet been independently confirmed by Mercado Bitcoin. The incident comes just days after the record $6.3 billion Binance hack, renewing scrutiny around the security of centralized cryptocurrency exchanges.
Following the incident, Mercado Bitcoin temporarily halted deposits and withdrawals while it investigated the affected systems and traced the movement of funds. The exchange said customer assets remain protected and that its teams are working to determine the full scope of the incident.
Seguimos trabalhando para restabelecer as operações com segurança e manteremos nossos clientes informados por nossos canais oficiais. Para contribuir com o monitoramento e o rastreamento de ativos nas redes blockchain, compartilhamos os endereços de destino…
Investigation Underway
The transactions identified by Hypernative appear to have been ordinary signed cryptocurrency transfers rather than transactions exploiting a smart contract vulnerability. That raises questions over how the attacker may have obtained the ability to authorize transactions from the affected wallets.
It remained unclear whether private keys, internal signing infrastructure, employee credentials, or another part of Mercado Bitcoin's systems had been compromised. The exchange has not yet disclosed the technical cause of the incident.