Symbiosis

The Bitcoin Bridge of cross-chain liquidity protocol Symbiosis has come under attack, and according to blockchain security firm Blockaid, the attacker exploited "BridgeV2" on BNB Chain to illegally mint roughly 46.1 billion syBTC. The attack occurred around 4:28 UTC on September 11, with the attacker exploiting a vulnerability in the Bitcoin Bridge. At the time Blockaid confirmed the incident, the attacker had sold about 4.39 WBTC through Uniswap v4 on Ethereum, obtaining roughly 336,000 dollars, or about 51.4 million yen at 153 yen to the dollar. Symbiosis isolated the Bitcoin Bridge from other systems and halted its proprietary BTC route, recovering about 15 BTC and holding it in a team-managed multisignature wallet. Routes on EVM-based networks as well as TRON and TON, along with the liquidity service "Octopools," were unaffected and are operating normally, and the protocol has resumed BTC swaps using Chainflip and THORChain, though its proprietary Bitcoin Bridge remains halted. Symbiosis is contacting affected liquidity providers individually and formulating a compensation framework, and has offered the attacker terms to receive 20 percent of the funds as a white-hat bounty, with a deadline of the 13th. The final damage figure is still being scrutinized and will be announced once confirmed.