Cronos confirms $9.2M slipped away before Tectonic exploit rollback

Cronos’s post-mortem put the Tectonic exploit’s affected borrowing at $120.4 million, with 7.6% transferred off-network before validators intervened.

Layer-1 blockchain Cronos said $9.19 million left its blockchain before validators halted the network during the Tectonic exploit, providing an official accounting of funds that were not reversed by its rollback. 

In Tuesday’s post-mortem report, Cronos said manipulated collateral values generated about $120.4 million in borrowing activity. Restoring the network to its pre-exploit state reversed about $111.2 million, leaving 7.6% of the affected funds outside of the network. 

The disclosure confirms the scale of the incident after earlier estimates placed the amount affected at about $75 million. It also puts the amount transferred off Cronos at $9.19 million, above the $8.3 million previously traced to Ethereum by blockchain data provider Bitquery.

Cointelegraph previously reported that one transaction emptied nine Tectonic lending markets through 11 transfers involving stablecoins, Bitcoin, Ether and other assets. 

Bitquery said the attacker deposited $5 million, then repeatedly borrowed and redeposited TONIC through a 98-cycle loop while purchasing the thinly traded token. The activity drove TONIC’s price nearly 300-fold higher as Tectonic’s price feed followed. 

Cronos said Tectonic detected the activity at 12:49 UTC on Aug. 30, and validators halted the network at 14:32:47 UTC. Block production resumed at 23:49:01 UTC after balances were restored.

Related: Liquid ‘white hats’ return $270M in Bitcoin as network prepares restart

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