Mercado Bitcoin, the largest crypto exchange in Brazil, has suspended deposits and withdrawals after what it described as an internal security incident detected overnight. The company said it contained the issue and is investigating while tracing assets and coordinating with authorities.

Blockchain monitoring has pointed to potentially significant losses, though several key details remain unconfirmed. Security firm Hypernative estimated that more than $40 million moved out of wallets attributed to Mercado Bitcoin, while the exchange said there was no loss to clients and no data leak.

Exchange confirms incident and pauses transfers

Mercado Bitcoin acknowledged the security event after multiple blockchain reports said the platform had been hacked. In its public statement, the exchange said deposits and withdrawals were temporarily suspended as a preventive step while internal teams investigate what happened.

The company said the incident had been detected and contained. It also stated that client funds were not lost and that no user data was exposed, although it did not specify how much, if any, of the affected assets belonged to the exchange itself.

Blockchain analysts tracked activity across many networks

According to Hypernative, the suspected attack involved wallets linked to Mercado Bitcoin on at least 10 different blockchains. The networks cited included Bitcoin, Ethereum, Solana, Tron, Polygon, Arbitrum, Avalanche, BNB Smart Chain, and Stellar.

The first suspicious transactions were reported around 11 p.m. on Sunday in Brazil. Hypernative said most of the funds were transferred to newly created addresses believed to be associated with the attacker, suggesting a coordinated operation rather than isolated wallet activity.

How the transfers were signed is still unclear

One of the main unresolved questions is how the outgoing transactions were authorized. Hypernative said the movements looked like ordinary transfers signed as if they had been approved by the original wallets, even though the destination addresses appeared suspicious.

That has left open the possibility of compromised private keys or a broader failure in the exchange’s infrastructure. The source of the incident, however, has not been confirmed, and Mercado Bitcoin has not publicly explained the technical cause.

Loss estimates and customer impact remain uncertain

Hypernative’s estimate of roughly $40 million in losses has not been independently confirmed by the exchange. Mercado Bitcoin’s own statement focused on containment efforts and its claim that there was no loss to clients, leaving unanswered whether the moved assets were corporate funds, customer assets, or some combination of both.

Other important details are still unknown, including the full amount ultimately affected and when normal deposit and withdrawal services will resume. Those points remain central to understanding the practical impact of the incident on the platform and its users.

Next steps depend on the ongoing investigation

For now, the confirmed next step is Mercado Bitcoin’s investigation into the incident, alongside asset tracing and coordination with authorities. The exchange said it will provide regular updates as more information becomes available.

The case also arrives shortly after another major crypto security shock, with the source article noting that it follows the record $6 billion Binance hack. Even so, the facts around the Mercado Bitcoin incident are still developing, and the exchange’s own findings will likely determine the clearest picture of what happened.

Source: beincrypto.com