BounceBit Shuts Down L1 Blockchain After $286.5M Token Heist

YZi Labs-backed BounceBit has announced it will shut down its standalone Layer 1 blockchain after an attacker exploited a flaw in the network's authorization system, draining 286.5 million BB tokens from nine accounts.

The attack occurred between August 19 and 20, with no theft of private keys involved. The attacker used primary accounts and 15 single-use contracts to exploit the weakness, allowing unauthorized accounts to become funding sources.

BounceBit has halted block production and will reissue BB as a BEP-20 token on BNB Chain using a snapshot of balances recorded at block 20,697,260 before the attack. The stolen tokens will not be included in the new supply.

Holders do not need to take any action during the reissuance process, and staked and unbonding balances will receive credits based on the snapshot. BounceBit has warned holders to avoid unofficial migration links or newly issued BB contracts.