Mercado Bitcoin wallets show post-hack transfers after $46M theft

Mercado Bitcoin, one of Brazil’s largest cryptocurrency exchanges, confirmed a security incident on Monday that blockchain analysts estimated drained more than $49 million from its wallets. Despite the company’s announcement that it had suspended deposits and withdrawals, addresses associated with the incident continued to receive funds for hours afterward.

Senior security engineer at Certik, Dickson Wu, published an initial post-mortem of the incident, saying the attackers “picked at eight small chains for four hours,” including Base, Optimism and Arbitrum. The attack then moved to the company’s main hot wallets before transferring tiny amounts of Ether (ETH) from 27,160 different addresses.