According to Wu Shuo, @shoucccc, co-founder of security agency fuzzland, tweeted that the mortgage agreement Shezmu was hacked and about $4.9 million of ShezUSD was stolen.
The attacker exploited a collateral loophole that allowed anyone to mint ShezUSD and lent out a large amount of ShezUSD. Due to insufficient liquidity, these ShezUSD were only redeemed for about $700,000.
