Key facts
- Mercado Bitcoin said no customer lost money and no data leaked after identifying a security incident in one of its systems.
- The exchange published destination addresses on Ethereum-compatible chains, Bitcoin, Solana, Stellar and Tron for on-chain tracking.
- Hypernative preliminarily estimated suspicious transfers above $40 million across at least 10 blockchains, a figure the exchange has not confirmed.
- Tether CEO Paolo Ardoino said more than 4.5 million USDT connected to the incident was frozen.
- Mercado Bitcoin has not said which system was breached, how attackers gained access or when services will resume.
Mercado Bitcoin kept deposits and withdrawals suspended after identifying a security incident in one of its systems in the early hours of the morning, the Brazilian cryptocurrency exchange said in a Portuguese-language statement on X. It said it contained the incident and took the suspension as a preventive protection measure.
The exchange said no customer lost money and no data leaked. It did not say which system was compromised, how attackers gained access or whether any funds were taken, and it gave no date for resuming services.
Mercado Bitcoin later published destination addresses it identified on five networks, covering Ethereum-compatible chains, Bitcoin, Solana, Stellar and Tron. It said the addresses were released so others could identify and track the funds on-chain.
Blockchain security firm Hypernative flagged more than $40 million in suspicious transfers that may be linked to the incident in a preliminary analysis spanning at least 10 blockchains, including Bitcoin, Ethereum, Solana and Tron. The exchange has not confirmed that figure.
Tether CEO Paolo Ardoino said in a post on X that the stablecoin issuer froze more than 4.5 million USDT connected to the incident. USDT is a dollar-pegged stablecoin, and Tether can blacklist addresses holding it so the tokens cannot be moved, though a freeze does not by itself return funds to their owner.
The incident comes days after hackers drained more than $6 billion from Binance on October 29, a theft the FBI attributed to North Korea's TraderTraitor group. Binance has since reopened withdrawals and said it replenished about 95% of the affected assets. Mercado Bitcoin has not linked the two incidents and has not said who is behind its own.