Mercado Bitcoin Halts Withdrawals After Security Breach

Brazilian exchange Mercado Bitcoin has suspended deposits and withdrawals after identifying a security flaw in its systems. The company asserts that client funds remain protected and that no data breach occurred. The platform is currently working to contain the incident and investigate the underlying causes.

Blockchain security analysts estimate that the volume removed from the exchange's wallets exceeds $40 million. The attack involved multiple networks including Ethereum, Base, Optimism, and Arbitrum. These movements were executed through standard transfers rather than exploits in smart contracts.

In response, stablecoin issuer Tether blocked addresses linked to the attackers on the Ethereum and Tron networks. Approximately $6.2 million has been frozen by stablecoin issuers so far. The company has not yet released a timeline for the resumption of normal operations.

Mercado Bitcoin serves a base of 4.5 million users and received a $20 million investment from Tether in July. Relevant authorities have been notified of the case. The exchange stated that it intends to cover any financial losses resulting from the episode.