Key Takeaways
- A security breach on Symbiosis’s Bitcoin Bridge occurred on September 11, resulting in the creation of approximately 46.1 billion counterfeit syBTC tokens without backing
- The perpetrator successfully liquidated roughly 4.39 WBTC via Uniswap, securing approximately $336,000 in actual funds
- The protocol managed to retrieve about 15 BTC, currently secured in a team-managed multisignature wallet
- A white-hat bounty proposal worth 20% was extended to the attacker, with September 13 set as the acceptance deadline
- This marks the third Bitcoin bridge unbacking attack in recent weeks, following similar incidents on Liquid Network and Nomic
On September 11, 2026, cross-chain protocol Symbiosis fell victim to a security breach targeting its Bitcoin bridge infrastructure. The attacker identified and exploited a critical flaw in the BridgeV2 smart contract, enabling the creation of billions of unbacked synthetic bitcoin tokens.
Blockaid, a blockchain security company, was the first to publicly identify the attack. According to their analysis, the perpetrator generated approximately 46.1 billion syBTC tokens—a figure exceeding 2,000 times Bitcoin’s actual total supply. These fabricated tokens were transferred to a newly created wallet address.
Although the attacker created an enormous quantity of counterfeit tokens, market conditions severely limited their ability to monetize them. They managed to convert approximately 4.39 wrapped bitcoin via Uniswap on the Ethereum network, ultimately securing roughly $336,000. The remaining minted tokens found no liquidity or willing purchasers.
Following confirmation of the breach, Symbiosis immediately suspended all native Bitcoin routing operations. The team maintained functionality across other supported networks, including EVM-compatible chains, TRON, and TON. Additionally, the protocol’s Octopools feature continued operating without interruption.
Protocol Retrieves 15 BTC and Extends Settlement Offer
According to Symbiosis, the team successfully recovered approximately 15 BTC following the incident. Based on current market valuations, this represents roughly $1.15 million in assets. These retrieved funds are currently stored in a multisignature wallet controlled by the team.
The development team initiated contact with the attacker, presenting a white-hat bounty proposal valued at 20% of the compromised funds. This offer included a September 13 deadline for acceptance. Following this date, Symbiosis announced it would redirect the same 20% reward to any individual providing actionable intelligence that leads to additional fund recovery.
The protocol has begun direct outreach to impacted liquidity providers. A comprehensive compensation plan is currently under development, with detailed criteria scheduled for publication soon. Meanwhile, Bitcoin swap functionality has been reinstated through partnerships with third-party bridges Chainflip and THORChain, while the native bridge remains suspended.
Series of Bitcoin Bridge Compromises Continues
This attack represents the latest in an alarming trend. Over recent weeks, both Liquid Network and Nomic experienced comparable attacks involving the creation of unbacked Bitcoin-pegged tokens.
Blockstream’s Liquid Network experienced a breach where an attacker generated approximately 4,000 unbacked LBTC tokens and exchanged them for genuine Bitcoin. The attacker subsequently returned around 3,400 BTC, though Blockstream declined to provide a bounty for the remaining 598.5 BTC that remains unaccounted for.
Nomic suffered from a distinct vulnerability that remained undetected for several months under comparable circumstances. Each of the three incidents employed fundamentally identical methodology—exploiting Bitcoin wrapper protocols to generate excess tokens purportedly backed by real assets.
As of September 13, Symbiosis has not released a detailed technical analysis explaining the precise mechanism through which BridgeV2 was compromised. Additionally, no public confirmation has been made regarding whether the attacker accepted the bounty proposal.
Since its launch approximately five years ago, Symbiosis has facilitated over $10 billion in cumulative transaction volume. The protocol currently maintains approximately $7 million in total value locked across its platforms.
Get 3 Free Stock Ebooks
Discover top-performing stocks in AI, Crypto, and Technology with expert analysis.
- Top 10 AI Stocks - Leading AI companies
- Top 10 Crypto Stocks - Blockchain leaders
- Top 10 Tech Stocks - Tech giants
