Qubic has restarted its blockchain after an Oct. 18 security incident in which approximately 2.94 trillion QU tokens were stolen from 1,404 wallets in less than two hours, amounting to nearly $1.3 million. The network's validators, known as Computors, halted transactions at tick 85,371,949 to prevent further losses. By the evening of Oct. 19, the chain was processing transactions again.
Recovery Plan Approved
On Oct. 20, Qubic announced that its validators had approved a recovery plan, opened a claims portal, and begun sending payments to verified victims. Approximately 87.1% of the stolen tokens remained trapped on the blockchain after the shutdown, while cryptocurrency exchange MEXC froze an account holding the remaining 12.9%. Qubic placed affected onchain funds into protected escrow, allowing validators to begin returning cryptocurrency to verified owners.
Weak Wallet Seeds Exploited
The attack did not involve breaking Qubic's blockchain. Instead, the thief exploited weak wallet recovery seeds—the secret strings that give owners access to their cryptocurrency. Older versions of Qubic's wallet software used a random-number generator that was not secure enough to protect cryptocurrency. The flaw affected wallets created through browsers on iPhones and iPads, Safari on Macs, and older versions of Qubic's iOS application. Attackers could potentially reconstruct predictable recovery seeds and gain access without knowing the owner's password.
Qubic said it corrected the problem in wallet version 4.26.4, released around Oct. 19, replacing the weak generator with a more secure method. However, updating the software does not repair an old recovery seed. Anyone who created a wallet using the affected software must generate an entirely new wallet and transfer their funds. Simply opening the old wallet on another device will not make it safe.
Claims Process and Deadline
Victims can submit claims through Qubic's official recovery portal until May 1, 2027. Applicants must provide their affected wallet identity, a newly generated destination wallet, a signed ownership message, and supporting evidence. Approved claims face a seven-day dispute period before payment. Recovery of funds held at MEXC depends on the exchange and any law-enforcement proceedings.
Qubic has warned users that legitimate recovery assistance never requires surrendering a wallet seed or paying a fee.
