Cronos says $9.19M remains unrecovered after $120M Tectonic exploit

Cronos has confirmed that $9.19 million remains unrecovered after an attacker borrowed $120.4 million from Tectonic, while a validator-backed rollback reversed roughly $111.2 million in affected value. Summary Cronos says $9.19 million remains unrecovered after an attacker borrowed $120.4 million from Tectonic using manipulated TONIC collateral. Validators rolled back 10,961 blocks covering nearly two hours of transactions, restoring roughly $111.2 million in affected value. The attacker moved 7.6% of the affected funds off Cronos before the network was halted, putting them beyond the rollback. Cronos resumed block production around 11 hours after the attack and continues reconciliation work with exchanges, bridges and other platforms. According to a post-mortem published by Cronos on Monday, the attacker manipulated the price of TONIC, the governance token of lending protocol Tectonic, and used the inflated asset as collateral to borrow funds across nine markets on Aug. 30. The attack led Cronos validators to halt the Layer 1 blockchain at block 90,907,150 before agreeing to restore the network to block 90,896,188, the final block produced before the exploit began. The rollback returned affected balances to their pre-attack state and reversed approximately $111.2 million of the $120.4 million involved in the incident. However, funds that had already moved away from Cronos were outside the reach of the restoration. “The $9.19 million that left Cronos before the halt has not been recovered and is beyond the restoration’s reach,” the team said. Cronos rollback restored $111.2 million after Tectonic exploit The rollback discarded 10,961 blocks, representing 1 hour and 54 minutes of Cronos transaction history, according to the post-mortem. Transactions completed during that window were reversed regardless of whether they had any connection to the Tectonic attack. Cronos said validators had to weigh transaction finality against the amount of money still exposed when deciding how to restart the network. “It was a hard decision, taken together with the validators, weighing the finality users expect from a chain against the funds at risk,” Cronos said. “The alternative, restarting without restoring state, would have left the borrowed assets in the attacker’s control.” The final accounting substantially raises the value involved compared with early estimates published immediately after the incident. On Aug. 31, crypto.news reported the Cronos halt after onchain researcher Weilin Li initially estimated that approximately $75 million had been affected. You might also like: Cronos restarts network after emergency halt over Tectonic exploit Li’s early analysis found that most of the identified funds remained on Cronos when validators stopped block production, while roughly $6 million was believed to have reached Ethereum. At the time, neither Tectonic nor Cronos had released a final accounting of the assets involved.