Binance and Polymarket disclosed security incidents on Thursday. Binance, the world's largest cryptocurrency exchange by trading volume, said it was investigating a potential hack with an estimated total impact of about $6.3 billion. The company said its initial investigation suggested a compromised development operations engineer's laptop allowed an attacker to access a service container and submit unauthorized withdrawal transactions. Binance found no evidence of wallet private key leaks. The exchange has worked with blockchain partners to freeze around $3 billion in assets and said it will cover all losses. Deposits and withdrawals remain temporarily suspended.
Binance founder and former CEO Changpeng Zhao said on X that a hack seemed likely and expressed that user funds are safe. He noted that as a shareholder, he expects all user funds will be fully covered. Tether CEO Paolo Ardoino said the company froze more than $1.5 billion related to the potential Binance hack. Circle CEO Jeremy Allaire said the company froze over $800 million in connection with the incident.
Polymarket, the world's largest prediction market by trading volume, temporarily halted trading after users reported unauthorized withdrawals on Thursday. The company said one of its third-party providers was compromised. Trading resumed by 3 p.m. Eastern time. A Polymarket spokesperson told Business Insider that malicious activity occurred in the UK and that the company will reimburse affected users. A person familiar with the matter attributed the Polymarket hack to a compromised third-party provider called DebugBear, a web performance monitoring platform. Polymarket's US exchange was not halted and did not appear to be affected. The company was unable to confirm the amount stolen.
Binance and Polymarket face ongoing investigations into the extent of the breaches and the recovery of frozen assets.