Mercado Bitcoin Restores Read-Only Access After $49 Million Hack

Mercado Bitcoin began restoring read-only access to customer accounts in phases on Monday, one week after attackers drained an estimated $49 million from the Brazilian crypto exchange. Customers can view their holdings, but withdrawals remain unavailable.

The exchange scheduled access to begin at 19:00 UTC, with all accounts expected to be viewable by 21:00 UTC. The information reflects customers’ holdings on Nov. 2, the day of the attack.

In a video posted on Mercado Bitcoin’s X account, Fabricio Tota, the exchange’s vice president of new business, described read-only access as a way to reassure customers that their assets remained recorded on the platform. He explained that the company chose “a more conservative approach” to restore services and improve security.

Mercado Bitcoin plans to use company funds to replace the stolen assets, so customers will not bear the losses. Tota said nearly all assets were unaffected and that some stolen funds were frozen within hours of the attack being disclosed.

The exchange has not explained how the attackers accessed its wallets. Blockchain security analysts said the funds appeared to have been taken through standard transfers after the attackers gained access to wallet addresses, rather than through a smart contract exploit. Blockchain data company Bitquery reported that wallets linked to the attackers held most of the stolen funds that had not been frozen, including 106.07 bitcoin, as of Nov. 4.

The next recovery phase will require customers to confirm their registration details before moving funds. Mercado Bitcoin plans to restore withdrawals through Pix, Brazil’s instant-payment system, initially limiting withdrawals to bank accounts held in the customer’s name. The exchange has not announced a date for either change.

Mercado Bitcoin pledged on Nov. 4 to cover all losses with company funds. Stablecoin issuer Tether invested $20 million in the exchange in July.

Mercado Bitcoin is one of Brazil’s largest crypto exchanges. It reported more than 4.8 million customers and over 215 billion Brazilian reais, or about $39 billion, in cumulative transactions in late October.

Reviewed and fact-checked by Alex Panasenko on November 9.