CryptoSlate
An attacker exploited Symbiosis's native Bitcoin Bridge at about 04:28 UTC on Sep. 11. Blockaid said a transaction accepted as signed by Symbiosis's BridgeV2 system minted approximately 2^62 raw units of syBTC to a new BNB Chain wallet. The same beneficiary sold about 4.39 WBTC on Ethereum for roughly $336,000. Symbiosis recovered approximately 15 BTC, but liquidity providers still lack compensation terms and final exposure figures.
Why it matters
The 2^62 figure measures raw synthetic-Bitcoin units, not Symbiosis's final loss. Blockaid's $336,000 estimate covers the WBTC conversion it observed, while Symbiosis said accounting remains in progress. The recovered bitcoin is secured in a team-controlled multisig.
Symbiosis said only its Bitcoin Bridge was affected. EVM, TRON and TON routes remained operational, as did its relayer group. Bitcoin swaps through Chainflip and THORChain are back online, but the native bridge remains paused.
Market impact
Liquidity providers are waiting for confirmed loss and exposure figures, compensation criteria, and a status update on the native bridge. Symbiosis is contacting affected providers and building a framework, but has not disclosed eligibility, payout calculations, or payment timing.
Symbiosis offered a 20% white-hat bounty through Sep. 13, with the same percentage later available for information leading to recovery. It did not specify the cutoff time or timezone. Until the accounting and compensation plan are published, the 15 BTC recovery and Blockaid's proceeds estimate are not a final loss tally.
Frequently asked questions
-
When did the Symbiosis Bitcoin Bridge exploit occur?
The vulnerability was exploited at about 04:28 UTC on Sep. 11. Blockaid said the minted syBTC went to a newly created wallet on BNB Chain.
-
Does the 2^62 syBTC mint equal Symbiosis's final loss?
No. The figure represents raw synthetic-Bitcoin units, while Blockaid's $336,000 estimate covers the WBTC conversion it observed. Symbiosis said final accounting remains in progress.
-
How much Bitcoin did Symbiosis recover, and where is it held?
Symbiosis said it recovered approximately 15 BTC, secured in a team-controlled multisig.
-
Which Bitcoin routes remain available while the native bridge is paused?
Bitcoin swaps through Chainflip and THORChain are back online. The native Symbiosis bridge remains paused, while EVM, TRON and TON routes remained operational.
-
What compensation details are still missing for liquidity providers?
Symbiosis has not disclosed eligibility, payout calculations, or payment timing. Providers are also waiting for confirmed loss and exposure figures and a status update on the bridge.
TheBlock
CoinDesk
WatcherGuru
Glassnode