Bybit, a crypto exchange, lost around seventy percent of its customers' ETH holdings in a $1.5 billion hack.Hackers tricked the key holders of Bybit's cold wallet into signing a malicious transaction, allowing them to steal over 400,000 Ether.The hack was allegedly carried out by the North Korean 'Lazarus Group', a notorious hacking group.Despite the loss, Bybit assured that all client losses are covered, and the exchange is securing a bridge loan to support liquidity.