DeFi cross-chain protocol Symbiosis says it recovered 15 BTC after an exploit involving its Bitcoin bridge and offered the attacker a 20% bounty. The incident has renewed attention on the security risks facing cross-chain infrastructure and digital-asset protocols.

The claim was reported by The Block, which said the Symbiosis team recovered 15 BTC following the exploit and extended the bounty offer to the person behind the incident. Symbiosis publishes protocol updates on its official blog.

Symbiosis reports recovery of 15 BTC

According to the reported statement, Symbiosis recovered 15 BTC after the Bitcoin bridge exploit. The figure is attributed to the protocol, and the material available for this report does not independently verify the recovery on-chain.

The 15 BTC refers only to the amount Symbiosis says it recovered. It does not establish how much was taken in total, and it should not be interpreted as evidence that the incident has been fully resolved or that the attacker returned the funds. The recovery amount also cannot be used to determine whether any shortfall remains.

Cross-chain bridges have historically been among the most targeted components of DeFi infrastructure, since they custody pooled user assets as funds move between networks and concentrate value at a single set of contracts. That structural profile is why recovery claims in this category are watched closely across the sector, not only by users of the protocol involved.

Protocol offers attacker a 20% bounty

Symbiosis is offering the attacker a 20% bounty, according to the same report. The offer is not a completed payment or an accepted agreement, and there is no indication in the available material that the attacker has responded.

The disclosed information does not specify the amount to which the 20% would apply. It is unclear whether the figure would be calculated against the recovered 15 BTC, the total amount taken, or another amount. No deadline, conditions, or legal terms have been provided, meaning that the bounty cannot be converted into a specific BTC figure based on the information currently available.

Bounty offers of this kind are an established practice in DeFi incident response, in which a protocol attempts to recover stolen funds by allowing an exploiter to retain a portion of the assets. Whether the attacker engages, ignores, or declines the offer is typically the next development observers watch in cases negotiated this way.

Details of exploit remain unclear

The total amount taken during the exploit and any remaining loss have not been established. Without those figures, the scope of the Symbiosis Bitcoin bridge incident cannot be assessed against the 15 BTC the team says it recovered.

The available material also does not establish how the recovery was carried out, what technical vulnerability caused the exploit, or whether the bridge is currently operating. These are limitations of the information available for this report and do not indicate that Symbiosis has withheld details. Further updates could come through the protocol's own channels, including its official blog, and independent on-chain analysis may provide additional verification of the figures involved.

This article is for informational purposes only and does not constitute financial or investment advice. Cryptocurrency and digital-asset markets carry significant risk.