Ostium Exchange Hit with $23.75M Loss from Off-Chain Compromise

The Ostium exchange suffered a $23.75 million loss after its off-chain system was compromised, allowing attackers to drain funds from its liquidity vault.

The breach occurred on July 15 between 14:18 and 14:24 UTC, with the final figure of $23.75 million being confirmed by Ostium's own accounting.

Ostium's post-mortem investigation found that the attack began off-chain in the infrastructure that produces and signs price reports for trades.

The attackers used a compromised oracle signer key to push fabricated Bitcoin price reports through a legitimate forwarder, opening a position at an attacker-set price of $5,000 and closing it near $60,000 inside the same transaction.