Mercado Bitcoin, Brazil’s largest crypto exchange, hit by $46 million security breach

Mercado Bitcoin, Brazil's largest cryptocurrency exchange, confirmed Monday that it suffered a security incident involving approximately $46.3 million in assets, according to Arkham data.

"We identified and swiftly contained a security incident in one of our systems early this morning," the exchange said in a post on X. Mercado Bitcoin temporarily suspended deposits and withdrawals as a precaution while its teams investigate the incident, track the assets, and coordinate with authorities.

The exchange said the incident did not affect customers or result in a data breach. It also published the destination wallet addresses associated with the transactions to help blockchain security firms and other parties monitor and track the assets.

Tether CEO Paolo Ardoino confirmed that the stablecoin issuer had frozen more than 4.5 million USDT linked to the incident.

Meanwhile, Arkham analyst Emmett Gallic said the attacker was sweeping funds from older deposit addresses and selling memecoins and other altcoins.

Mercado Bitcoin's incident comes amid a string of security breaches and exploits across the crypto industry in recent days, following Thursday's $6 billion hack of Binance. That same day, Polymarket was hit by a $2.65 million exploit, in which it said a third-party provider was compromised.

Late Friday evening, blockchain analytics firm Chainalysis said its own customer data was accessed by an AI-assisted hacker. Of note, the firm said the incident was not related to the theft at Binance.

On Saturday, hackers hijacked a dozen DeFi websites registered with Name.com and stole about $138,000. Blockaid said the sites were rigged with a malware kit that tricks visitors into signing away their funds.