Brazilian cryptocurrency exchange Mercado Bitcoin has temporarily suspended deposits and withdrawals after identifying a security incident in one of its systems on November 2.
Summary
- Mercado Bitcoin has temporarily suspended cryptocurrency deposits and withdrawals after detecting and containing a security incident in one of its systems on November 2.
- The Brazilian exchange said customers had suffered no harm and no data breach had occurred, although it did not disclose which system was affected or whether any assets were stolen.
- Security teams are investigating the incident, tracking assets and coordinating with authorities, while the exchange has yet to announce when deposits and withdrawals will resume.
- The incident follows a series of security breaches across the crypto industry over the past week, including the October 29 Binance hack and subsequent restrictions across Aave markets.
In an official statement, the exchange said it detected the incident early Monday morning and quickly contained it, assuring customers that their funds were not affected and that no data breach had occurred.
The company did not disclose which system was compromised or provide an estimate of the assets involved. However, it confirmed that its security teams were investigating the incident and tracking assets while coordinating with the relevant authorities.
Mercado Bitcoin said the suspension of deposits and withdrawals was a precautionary measure intended to protect users while the investigation continued.
The announcement did not specify when the services would resume or whether other functions on the platform, including cryptocurrency trading, were affected.
Mercado Bitcoin investigates security incident as withdrawals remain suspended
According to the November 2 announcement, the security issue was identified in one of the exchange’s systems, although the company provided no technical explanation of how the incident occurred.
Its response included containing the affected system and temporarily restricting the movement of funds through deposits and withdrawals.
Mercado Bitcoin maintained that customers had suffered no harm and that their personal information had not been exposed. The statement did not identify any affected cryptocurrency, blockchain network or wallet address.
Despite confirming that its teams were tracking assets, the exchange did not say whether any cryptocurrency had been transferred without authorization or whether the investigation had identified suspicious transactions.
The company has not disclosed the number of accounts potentially involved in the incident or identified the system under investigation.
For customers, the immediate restriction concerns the ability to move cryptocurrency into or out of the platform. The exchange has not announced a timetable for restoring those services, leaving users waiting for another operational update.
Its security teams are working with authorities as the investigation continues, although the company has not named the agencies involved or disclosed whether any funds have been frozen.
Mercado Bitcoin said it would provide regular updates through its official communication channels as more information became available.
Recent crypto hacks have disrupted exchange operations
The incident follows a series of security breaches and emergency restrictions across the cryptocurrency industry over the past week.
On October 29, Binance suffered a major security breach that affected approximately $6.3 billion in cryptocurrency assets, prompting the exchange to temporarily suspend withdrawals while it investigated unauthorized transactions.
As previously reported by crypto.news, Binance’s initial investigation suggested that attackers had compromised an engineer’s laptop and gained access to internal infrastructure used to process withdrawals.
The exchange said it found no evidence that wallet private keys had been exposed, although attackers were able to initiate unauthorized transfers through the compromised environment.
Binance subsequently worked with blockchain security firms, stablecoin issuers and law enforcement agencies to trace the stolen cryptocurrency. By October 30, the company said roughly $3 billion worth of affected assets had been frozen on-chain.
The exchange pledged to cover customer losses using its Secure Asset Fund for Users and corporate funds, with more than $6.34 billion allocated toward replenishing the affected assets.
By November 1, Binance said it had replaced approximately 95% of the stolen assets and had begun restoring withdrawals in phases following additional security checks.
The attack prompted emergency measures beyond Binance’s own platform.
Decentralized lending protocol Aave temporarily restricted several markets after a wallet linked to the Binance attacker deposited 60 million USDT and borrowed 19,762 WETH before security controls took effect.
Aave’s guardians froze new deposits and borrowing across 175 V3 reserves and 117 V4 reserves, although users could continue withdrawing funds, repaying loans and liquidating positions.
The protocol reopened its V3 and V4 markets on October 30 after implementing additional risk controls. Aave maintained that its smart contracts had not been compromised during the incident.
BTCPay Server warns of unauthorized wallet withdrawals
Separately, Bitcoin payment processor BTCPay Server warned of unauthorized withdrawals from hot wallets connected to some installations, prompting an emergency security alert on November 1.
The open-source payment platform initially advised operators to shut down their servers while developers investigated reports of funds being drained.
Its subsequent investigation narrowed the suspected attack vector to installations running version 2.4.1 or earlier, according to the project’s security updates.
BTCPay Server had not disclosed the total value of cryptocurrency stolen or the number of installations affected when it issued its November 2 update.
The project asked affected operators to provide incident details and server logs to assist the investigation, while hosting providers including LunaNode took precautionary steps to shut down some installations.
