Qubic has resumed its blockchain operations following a major security breach that resulted in the theft of nearly $1.3 million worth of its native QU tokens from 1,404 user wallets. The incident led to an emergency network shutdown as validators moved to contain the damage.
Attack Targets Recovery Seeds, Not Blockchain
The theft occurred on October 18, when an attacker exploited vulnerabilities related to wallet recovery seeds, rather than flaws in the blockchain itself. Approximately 2.94 trillion QU tokens were taken in less than two hours, prompting Qubic’s network validators, referred to as Computors, to freeze activity at tick 85,371,949 to halt further losses.
Qubic, a distributed ledger project focused on decentralized computation and token distribution, stated that the exploit centered on weak random-number generation used in older wallet versions. These weaknesses made some recovery seeds predictable and susceptible to unauthorized access.
Wallets affected were those created on iPhones and iPads, Safari browsers on Mac devices, and legacy versions of the Qubic iOS wallet app. The update addressing this vulnerability was released as wallet version 4.26.4 around October 19, replacing older, insecure random-number generation methods with a more robust approach.
Opening a compromised wallet on a different device does not resolve the issue. Qubic has urged users with wallets generated from affected platforms to create a new wallet and transfer their assets accordingly.
Mini dictionary: Computor — In the Qubic network, Computors are validator nodes responsible for consensus and decision-making processes, including transaction validation and recovery measures.
Restoration and Recovery Efforts
By the evening of October 19, blockchain operations had resumed. Qubic’s validators subsequently approved a recovery plan, launching a claims portal and initiating the first payments to verified victims the next day.
Qubic noted that the Computor quorum had unanimously authorized the recovery process, confirming that the reclaim platform was active and that initial fund returns had begun for approved users.
Recovery was made possible as about 87.1% of the stolen tokens remained onchain following the emergency pause. Crypto exchange MEXC identified and froze the account containing the remaining 12.9% of stolen QU tokens, pending further investigation and possible legal action.
| Wallet Status | Percentage of Stolen QU | Recovery Action |
|---|---|---|
| Onchain (paused) | 87.1% | Held in escrow, being returned to verified claimants |
| MEXC exchange | 12.9% | Account frozen, awaits further proceedings |
Claims Process and Ongoing Precautions
Victims of the breach can submit claims through Qubic’s official recovery portal until May 1, 2027. To file a claim, applicants must provide the identity of their compromised wallet, details of a new replacement wallet, a signed ownership statement, and supporting documentation. Each successful claim is subject to a seven-day dispute period before payment is processed.
Qubic has warned users to be vigilant against recovery-related scams. The project emphasized that genuine recovery support will never ask for private seed phrases or request payment.
Qubic’s team underlined, “Legitimate support never requires providing a wallet seed or transferring upfront fees.”
The first funds were returned to victims on October 20. The claims portal remains available through May 2027, providing an extended window for affected users to seek restitution. Recovery of QU tokens trapped on the MEXC exchange will depend on future decisions from the exchange operator and any law enforcement action.
