A reentrancy exploit in the Ethereum-based Visor Finance DeFi protocol allowed hackers to pull 8.8 million VISR tokens out of the network, equivalent to about $8.2 million. The VISR token went from trading at around $0.93 to around $0.04, losing more than 95% of its value. The Visor team subsequently announced that they would perform a token migration to compensate affected users. Visor has suffered other hacks since its launch earlier in 2021, despite having undergone several audits.

Total loss estimated at $8,200,000.