Mercado Bitcoin Says $11 Million Frozen in $38 Million Breach

Mercado Bitcoin said a security incident discovered early Monday, Nov. 2, affected one of its systems. The Brazilian exchange halted deposits and withdrawals as a precaution while it investigates, traces assets and coordinates with regulators.

In a later update, the company estimated that about $38 million in assets were involved. It said $11 million had been frozen through work with Tether, Circle, Paxos and BRL1, as well as blockchain analytics firm Chainalysis. The exchange said additional assets that could be frozen had been identified and efforts to freeze them were continuing.

Mercado Bitcoin said no customer assets were lost and no data was exposed. The company has not disclosed how its system was accessed or set a date to restore deposits and withdrawals. It said services will resume only after security conditions are fully restored, with timing to be announced through its official channels.

The Brazilian exchange says it has 4.8 million customers and has operated for more than 13 years.