Yu Xian, the founder of SlowMist, said that four sets of mnemonics of a certain user were leaked, and the funds in the four corresponding wallet addresses were stolen. From the perspective of the on-chain operation, after receiving the funds, the hacker exchanged them all for ETH and then washed them away through FixedFloat. The longer the mnemonics/private keys are used online and the more people they are distributed to, the more likely they are to be leaked, and the more difficult it is to investigate the cause of the leak.