Hackers mint trillions in fake Bitcoin, but 15 BTC bridge recovery leaves liquidity providers unpaid

Cross-chain protocol Symbiosis said it recovered approximately 15 BTC after an attacker exploited its native Bitcoin Bridge, but affected liquidity providers still lack compensation terms as a Sep. 13 bounty window nears its unspecified cutoff.

The vulnerability was exploited at about 04:28 UTC on Sep. 11, according to the protocol's incident statement. Symbiosis said only the Bitcoin Bridge was affected and that its other routes and components remained operational. It specifically listed routes spanning EVM chains, TRON and TON as unaffected, and said its relayer group continued operating to secure the network. The protocol said the recovered bitcoin is secured in a team-controlled multisig.

The 15 BTC figure is simply the amount Symbiosis says it recovered to date. The protocol said final accounting remained in progress and that it would publish confirmed figures in another update.

Security firm Blockaid reported that a transaction accepted as signed by Symbiosis's BridgeV2 system minted approximately 2^62 raw units of syBTC, a synthetic representation of bitcoin, to a newly created wallet on BNB Chain.

Blockaid said the same beneficiary sold about 4.39 WBTC on Ethereum, realizing roughly $336,000 in WBTC proceeds at the time of its alert. That figure covers value Blockaid observed the attacker convert. It does not establish Symbiosis's final loss or the total exposure of liquidity providers.