According to MozaicFi, the theft had been perpetrated by a rogue developer who was able to gain access to a private key held by a core team member. They also claimed that a simultaneous large sale of the Mozaic token resulted in cascading liquidations.
In good news for the project, the attacker moved around 90% of the stolen funds to MEXC, a centralized cryptocurrency exchange that was able to freeze the thief's access to the funds.