Mercado Bitcoin Halts Withdrawals After Security Breach, $4.5M USDT Frozen

Mercado Bitcoin suspended deposits and withdrawals on Nov. 2 after detecting a security incident affecting one of its systems. The Brazilian cryptocurrency exchange said it contained the incident quickly, with no customer losses or data breach identified.

The exchange is investigating the incident, tracking suspicious transactions and cooperating with authorities. However, it has not disclosed how the attacker gained access. Tether has frozen $4.5 million in USDT connected to the incident.

Mercado Bitcoin Tracks Suspicious Crypto Transfers

Mercado Bitcoin released wallet addresses across Ethereum-compatible networks, Bitcoin, Solana, Stellar and Tron to help investigators trace the funds.

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A report shared by Opsek founder Pablo Sabbatella identified significant outflows between 06:19 and 06:53 UTC. During that period, wallets transferred funds to newly created addresses across Ethereum, Solana, Tron, Polygon, Arbitrum, Avalanche, BNB Smart Chain and other networks.

According to the report, the attacker received approximately 2,852 ETH, 106 $BTC, 10,700 SOL, 6.7 million XLM and 77,000 AVAX. The wallets also held more than 200 other tokens. The report described the transfers as regular transactions rather than a smart contract exploit.

Tether Freezes Funds Amid Wider Security Concerns

The Mercado Bitcoin incident comes days after the FBI attributed Binance’s $6 billion-plus hack to North Korea’s TraderTraitor group. However, investigators have not established any connection between the two incidents.

Brazil’s central bank previously develop a cryptocurrency threat-monitoring system with Hypernative. Mercado Bitcoin and Foxbit appeared among the planned participants. However, Mercado Bitcoin has not confirmed whether it used the system during its investigation.

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