$48.6 Million in Transfers in Mercado Bitcoin Hack as Operations Temporarily Suspended
Key Facts
Brazilian platform Mercado Bitcoin temporarily halted deposits, withdrawals and asset trading after detecting a security incident overnight, while an analysis by Bitquery estimated outgoing transfers from its wallets at about $48.6 million. In its first update on the morning of November 2, the platform said it had detected and quickly contained the incident, and had begun tracking the assets and coordinating with authorities. It later said affected assets totaled about $36.3 million and that it had blocked the equivalent of $12.9 million. The company’s estimates differ from Bitquery’s tracking of on-chain transfers, and the company’s figures also changed between updates. Mercado Bitcoin pledged to cover customer losses, while giving no date for the return of its services.
Mercado Bitcoin said the incident affected hot wallets used for daily operations, while assets held in cold wallets remained outside its scope. In its first update, the company said customers had suffered no harm and their data had not been leaked. Its FAQ confirmed that logins, deposits, withdrawals and asset trading had been temporarily suspended, without providing a timeline for resumption. It said the shutdown was a precaution while it handled the incident, and that updates on the return of service would be issued through its official channels. The company said it would restart the platform only after confirming that operations were safe for users.
In an update dated the evening of November 2, Mercado Bitcoin said it had blocked about $11 million with the help of partners, while the value of assets not yet blocked stood at about $38 million. The latest open official update gave a different estimate, putting affected assets at about $36.3 million and blocked amounts at about $12.9 million. Bitquery, in a separate analysis, calculated about $48.5 million in transfers across ten blockchain networks, noting that most funds moved through Ethereum and then Bitcoin. A broader analysis for the period from November 2 to 3 estimated observed transfers at about $48.6 million across the ten networks. The differing figures reflect differences in the measurement scope and timing between the company’s estimate and the tracking of on-chain transfers.
Bitquery’s analysis showed that the transfers involved the platform’s wallets across ten networks, and that 36,042 customer deposit addresses on Ethereum were emptied on November 2. CoinDesk reported that the company would cover user losses, which the outlet estimated at between $38 million and $40 million. The report said partners, including Tether, Circle and Chainalysis, helped freeze $11 million in assets. In a separate estimate, Bitquery said Tether froze $5.9 million in assets and Paxos froze $1.5 million. The Block reported that Tether froze more than 4.5 million units of USDT linked to the incident.
Mercado Bitcoin said the investigation was ongoing and that it could not currently confirm a link between the incident and the Binance hack. The company did not say how the attacker obtained signing authority, while CoinDesk reported that the largest transfers took place between 06:19 and 06:53 UTC on November 2. The incident came days after the Binance hack, which the company said resulted in the theft of assets worth more than $6 billion. Binance said it had worked with blockchain industry partners to freeze about $3 billion in affected assets. Mercado Bitcoin said the date for resuming its services would be announced in a later update, and that the platform would not return until the safety of its operations had been verified.