Symbiosis Bridge Hacked, $336K Assets Stolen; Reward Offered for Return

The Symbiosis cross-chain protocol's Bitcoin bridge suffered an attack, leading to the unauthorized withdrawal of assets valued at approximately $336,000 (about ₩451 million). The attacker issued a large amount of uncollateralized syBTC on the bridge before exchanging 4.39 WBTC. Symbiosis confirmed in an official X post that the Bitcoin bridge vulnerability was exploited around 1:28 p.m. KST on September 11, halting related routing. The team has recovered approximately 15 BTC and secured it in a multi-signature wallet managed by the team, stating that EVM chains, TRON, TON routing, and Octopools were unaffected. Blockaid observed that around 46.1 billion uncollateralized syBTC was issued on the bridge contract, though only 4.39 WBTC was sold by the attacker, resulting in a loss of approximately $336,000. Symbiosis has offered a 20% reward for the return of funds, with a deadline set for September 13. If no voluntary return occurs by then, the same percentage will be paid to whistleblowers who provide information aiding fund recovery.