Mercado Bitcoin halts withdrawals after $40 million exploit across 10 chains
Security & Exploits ·
Brazil's largest crypto exchange paused deposits and withdrawals after an overnight security incident led to an estimated $40 million in suspicious outflows spread across 10 different blockchain networks.
The exchange moved to suspend account activity following what it described as a cyberattack, according to coindesk.com. The decision to freeze both deposits and withdrawals came as the platform worked to contain the fallout from the breach, with the scale of the drain spanning a wide set of networks rather than a single chain, complicating efforts to trace and halt the movement of funds.
Security firm Hypernative put the estimated value of the suspicious transfers at more than $40 million, a figure echoed across multiple reports on the incident, per wublockchain.xyz. That the activity touched 10 separate blockchains points to a broad compromise rather than an isolated wallet or contract failure, though the exact mechanism behind the exploit has not been disclosed.
Despite the size of the reported losses, Mercado Bitcoin has maintained that no client funds or personal data were compromised in the incident. The company has not detailed how it arrived at that assessment or whether the $40 million figure reflects funds drawn from its own treasury, operational wallets, or another source entirely.
The episode marks a significant security event for Brazil's crypto market given Mercado Bitcoin's position as the country's largest exchange. Coverage of the incident has been corroborated across several outlets, converging on the same $40 million estimate and the 10-chain scope of the activity, even as specifics about the attack vector remain unconfirmed.
What remains unresolved includes the precise cause of the breach, whether any funds can be recovered or frozen, and when deposits and withdrawals will resume. It is also unclear whether the company's assurance that client assets were untouched will hold up as investigators and outside security researchers continue examining the on-chain activity.