Overview
Mercado Bitcoin, described as the largest cryptocurrency exchange in Brazil, confirmed a cyberattack after blockchain security firms observed more than $46 million leaving the platform, The Record reports. The company has not confirmed the figure.
What happened
Outflows began late Sunday night. On Monday morning the exchange suspended all deposits and withdrawals and confirmed a cybersecurity incident. It said its "teams are mobilized – investigating the case, tracking the assets" and working with authorities, and published destination addresses for the stolen funds. It pledged to restore the platform in the coming days.
Disputed customer impact
Mercado Bitcoin says the attack did not harm its roughly 4.5 million customers or cause a data breach. Several blockchain security experts dispute this, pointing to on-chain evidence that hackers drained some customer wallets.
Recovery efforts
- Tether CEO Paolo Ardoino said Tether froze about $4.5 million of the stolen funds
- Other platforms froze roughly another $2 million
- Chainalysis said it is tracking the coins so the industry can identify, freeze and disrupt them
Context
The attack follows days after a $6.3 billion theft from Binance, attributed by the FBI and U.S. Secret Service to North Korean hackers. Chainalysis also disclosed its own security incident the previous week. No attribution has been made for the Mercado Bitcoin attack, and the attack vector has not been disclosed.
Guidance for users
- Expect further updates from the exchange; avoid links in unsolicited messages claiming to help recover funds
- Keep long-term holdings in self-custody where practical
- Watch for phishing that exploits the incident