Cronos Validators Rewind Chain After $75M Hack

Cronos, a blockchain network, recently rolled back its own chain to undo a $75 million hack. The attack occurred on Tectonic, a lending protocol on Cronos, where an attacker pumped up the price of TONIC by 100 times in just 20 minutes using roughly $600,000.

The attacker then supplied 364.6 trillion inflated tokens as collateral and borrowed approximately $75 million from other depositors. However, only about $6 million escaped to Ethereum before the halt, leaving the remaining $69 million frozen at Cronos addresses until the rollback wiped the attack transactions from the canonical chain.

Cronos validators halted block production on Aug. 30, rolled back over 10,000 blocks, and restored the chain to its pre-exploit state. This decision was made quickly, without much debate, and sparked a fierce discussion about whether a blockchain that can be rewound on command deserves to call itself decentralized.