Brazilian cryptocurrency exchange Mercado Bitcoin suspended deposits and withdrawals on Monday after wallets linked to it were drained across at least 10 blockchain networks in a security incident that specialist firms estimate caused losses of more than $40 million.

The incident comes days after the hack of Binance, which the U.S. Federal Bureau of Investigation (FBI) attributed to the North Korean hacking group TraderTraitor. The breach resulted in the theft of crypto assets worth more than $6 billion, according to information in the report.

In the details of the attack, Pablo Sabbatella, founder of OpSec, a company specializing in cryptocurrency security, shared a report stating that the largest fund transfers originated from wallets across several networks, including Ethereum, Solana, Tron, Polygon, Arbitrum, Avalanche, BNB Smart Chain (BSC), and Stellar. Most of the balances were transferred to new addresses.

According to the report, the attacker took assets including approximately 2,852 Ether, 106 Bitcoin, 10,700 Solana, 6.7 million Stellar (XLM), and 77,000 Avalanche (AVAX), as well as more than 200 other digital tokens.

The report noted that the transfers were carried out through routine transactions and did not result from exploiting a vulnerability in a smart contract. The method by which the attacker obtained signing permissions remains unknown.

Mercado Bitcoin said in a statement on its X account that it had detected and quickly contained a security incident, emphasizing that neither customer funds nor data had been compromised.

It explained that suspending deposits and withdrawals was a precautionary measure while investigations, asset tracing, and coordination with the relevant authorities are completed.

So far, the party responsible for the attack has not been identified, and there is no publicly available evidence linking it to the Binance platform breach, despite the incidents occurring at around the same time.$BTC