Symbiosis Recovers 15 BTC from Bridge Exploit, Offers 20% Bounty for Hacker Info

Cross-chain liquidity protocol Symbiosis has recovered 15 Bitcoin, worth approximately $1.1 million, following a Bitcoin bridge exploit it disclosed on Friday. The recovered BTC was transferred into a team-controlled multi-sig wallet, and the protocol confirmed that all routes remain operational, according to a Friday post on X. The exploit specifically targeted Symbiosis' native Bitcoin bridge, which remains paused while the team investigates.

Blockchain security firm Blockaid, which flagged the exploit, reported that the attacker's address minted 46.1 billion unbacked tokens from the protocol's Bitcoin bridge but realized net proceeds of just 4.3 Wrapped Bitcoin (WBTC), valued at around $336,000. DefiLlama clocked losses in line with that figure, though Symbiosis has not yet disclosed its final accounting. The protocol has also not clarified how the 15 BTC it recovered relates to the $336,000 in net proceeds attributed to the attacker.

After the hacker's deadline to return the stolen funds in exchange for an initial 20% white-hat bounty expired on Sunday, Symbiosis is now offering a 20% bounty to anyone who provides information leading to asset recovery. The protocol stated it will reveal a compensation framework for affected liquidity providers in due course.

The incident is the latest in a string of bridge exploits challenging the DeFi sector. In June, Secret Network suffered an "infinite mint" exploit that drained approximately $4.6 million, while in May the Verus-Ethereum bridge lost 5,402 Ether (then worth around $11.6 million) in a forged cross-chain transfer attack, with the attacker returning 75% of the funds after being offered a 25% white-hat bounty.