Major Security Breach Forces Mercado Bitcoin to Pause Withdrawals Across Multiple Blockchains

Mercado Bitcoin temporarily halted deposits and withdrawals after several wallets associated with the exchange were emptied across at least ten different blockchains. Security firms place the estimated losses at over $40 million, making this a significant incident for the Brazilian crypto platform.

Reports indicate the largest outflows occurred within a narrow window early in the UTC day, during which wallets on networks such as Ethereum, Solana, Tron, Polygon, Arbitrum, Avalanche, BSC and Stellar forwarded substantial balances to newly created addresses.

Details of the asset movements and current holdings

According to a report relayed by Pablo Sabbatella of Opsek, the attacker now appears to control approximately 2,852 ETH, 106 BTC, 10,700 SOL, 77,000 AVAX and about 6.7 million XLM, along with more than 200 additional tokens. The transfers were executed as standard transactions rather than via a smart contract exploit, leaving the mechanism of signing access unclear.

Exchange response and coordination

In a statement posted on X, Mercado Bitcoin said it had “identified and swiftly contained” the security incident and asserted that there was no customer harm and no data breach so far. As a precautionary measure, deposits and withdrawals remain paused while internal teams and external partners investigate, monitor asset flows and work with law enforcement.

The exchange has published destination addresses for affected EVM chains, Bitcoin, Solana, Stellar and Tron to assist others in tracking the stolen funds.

Wider context and third-party actions

Although the incident follows closely after a separate, massive theft attributed by the FBI to North Korea-linked actors from another platform, no public evidence currently links this breach to that prior attack. Mercado Bitcoin has not made any attribution.

Notably, Tether confirmed that around $4.5 million in USDT connected to the incident has been frozen, demonstrating ongoing third-party mitigation efforts.