The attack on Brazil's largest crypto exchange Mercado Bitcoin has turned into a prolonged phase of dumping stolen assets. The attacker, who gained access to the platform's funds, is systematically converting the stolen tokens into ETH, creating additional pressure on the quotes of the affected altcoins.
For the exchange's own clients, the situation looks less alarming: company representatives assure that user funds and personal data were not affected. Meanwhile, the investigation continues, and the actual scale of the damage has not yet been officially confirmed.
Mechanics of dumping the stolen assets
The attacker accumulated 31 altcoins in a single wallet and exchanged them for approximately 163 ETH (about $378,000). The entire sum was then transferred to another address, while the sell-off of tokens through the already identified wallet continues.
Mercado Bitcoin confirmed the breach two days earlier, when an outflow of funds totaling over $40 million was recorded across ten or more blockchain networks. The company temporarily suspended deposits and withdrawals. 2,852 ETH, 106 BTC, 10,700 SOL and other assets were linked to the suspicious addresses.
Tether, the issuer of the USDT stablecoin, has reportedly frozen tokens linked to the incident worth more than $4.5 million.
Hacks are getting cheaper for attackers
The scheme used against Mercado Bitcoin mirrors the pattern previously described in an investigation of a covert breach of an unnamed European organization with damage exceeding $133 million. The stolen funds are transferred into ETH and the anonymous cryptocurrency Monero (XMR) through instant exchangers and cross-chain bridges.
Carrying out such attacks is becoming increasingly cheap: a server belonging to a partner of the ransomware group The Gentlemen was discovered, where an AI agent performed virtually all the work — from network reconnaissance to data theft and calculating the ransom amount. A human only had to set the tasks, and the cost of running the model was about $4 per victim company.
The largest platforms are also vulnerable: on October 29, attackers withdrew about $6.3 billion from Binance's hot (internet-connected) wallets. The exchange promises to cover clients' losses and is buying up the missing tokens on the market and through over-the-counter deals until full coverage is achieved for each asset.
Cryptalist analysis: The ongoing sell-off of 31 altcoins through the identified wallet is creating a local downward impulse in the affected assets, especially in low-liquidity segments where even moderate selling volume can move the price. The incident once again highlights exchange security as a systemic risk of the crypto market and strengthens the case for decentralized asset storage and institutional standards of custodial risk management.