Grim Finance, the “compounding yield optimizer” DeFi platform, was hacked. According to them, attackers exploited a bug in the platform to perform a reentrancy attack that netted them $30 million. Grim, indeed. A cryptocurrency watchdog group, RugDoc, opined that the exploit was possible because of very basic mistakes in implementation, and wrote, “Hopefully all projects can draw lessons from this incident that there is much knowledge most experienced solidity devs have at hand. If you haven’t acquired this yet, don’t build multi-million dollar projects. Don’t get audits from companies which everyone knows are useless.” This was apparently a dig at Solidity Finance, who had performed an audit several months prior to the hack and found that “ReentrancyGuard is used in relevant locations to preent[sic] reentrancy attacks.”

Total loss estimated at $30,000,000.