Blockchain Networks Halt Production in Emergency Response to Exploits

Three major blockchain networks - Cronos, Ontology, and ICON - took emergency measures to halt production within four days of each other. Each network used different methods to stop producing blocks, with Cronos replacing part of its canonical history in the process.

Cronos's incident occurred after an exploit affected Tectonic, a decentralized lending protocol running on top of Cronos. The validators halted the network by consensus and restored it to a state before the incident. This decision effectively discarded transactions and state changes that occurred after the chosen restore point.

The exact amount lost in the Cronos incident is still pending, with estimates ranging from $6 million to $75 million borrowed after TONIC's price was manipulated. TRM Labs estimated that around $68.7 million was reversed on Cronos, while Bitquery reported a larger gross outflow of about $8.3 million on Ethereum and 10,961 discarded blocks.

Ontology suspended block production before confirming malicious attack activity, but chose not to replace accepted state or rollback transactions. The network's halt left accepted state intact and stopped new settlement, with users facing operational delays rather than confirmed losses.