Qubic Restarts Blockchain, Opens Recovery Claims After $1.4M Hack

Qubic, a layer-1 blockchain, has restarted network processing and begun a recovery procedure after a wallet seed vulnerability enabled an attacker to siphon QU tokens from thousands of accounts. In its latest update, the project said the incident drained roughly $1.4 million worth of QU tokens from 1,404 accounts.

Qubic also pointed users to a new claims workflow and reiterated that it has fixed the underlying issue in its web wallet. Network status information from the project’s explorer indicates the chain resumed processing after being halted to limit further movement of potentially compromised funds.

Key takeaways

• Qubic restarted its blockchain after halting the network to stop additional transfers following a predictable wallet-seed exploit.
• The project said the attacker drained about $1.4 million in QU tokens across 1,404 accounts.
• Validators (“Computors”) approved a recovery plan, and Qubic has launched a dedicated claims platform for affected holders.
• Wallet seeds generated via the Qubic web wallet on certain Apple devices and browsers were vulnerable to weak randomness.
• Users can submit claims until May 1, 2027, and Qubic urges anyone using pre-fix web wallets to update and migrate funds.

Network restart and the recovery process

According to Qubic’s blockchain explorer, the network resumed processing ticks at 8:00 pm on Oct. 19 and advanced beyond tick 85,371,949—an area where processing had been paused on Sunday.

Qubic said that its validators, known as Computors, approved a recovery plan. The project also described the launch of a claims platform designed to allow affected wallet holders to retrieve tokens tied to the compromised wallets.

How the exploit worked—and why the chain was halted

Qubic halted the network to prevent further movement of stolen funds after attackers took advantage of wallet seeds generated by vulnerable wallet software. The project’s explanation centers on predictability: the vulnerability allowed wallet seeds to be generated in a way that could be inferred or reproduced rather than securely randomized.

Qubic specified that the issue affected wallet seeds generated using its web wallet on certain Apple devices and browsers. In those cases, an insecure random-number generator could produce predictable seeds, which in turn could make corresponding wallets susceptible to unauthorized token movement.

That operational response—pausing the chain before continuing recovery—highlights the tradeoff Qubic faced: keeping the network running while addressing active risk from already-stolen funds and potentially additional compromised transfers.

Claims platform opens for affected users

Qubic directed impacted users to check their address and submit a claim through its reclaim platform: weak-seed-reclaim.qubic.org. The project states that users have until May 1, 2027, to submit their claims.

For investors and traders, claims timelines can matter because they shape when liquidity tied to affected wallets may return to normal circulation. For wallet holders, the immediate concern is less about price signals and more about whether their funds are recoverable via the process Qubic has set out.

Wallet fix released; users are warned to migrate

Alongside the restart, Qubic said it has fixed the seed-generation flaw in the latest version of its web wallet. The project linked to its wallet repository and described the specific update needed for security remediation.

Qubic warned users that if they created their wallet with the Qubic web wallet before version 4.26.4—released on Oct. 19—they should treat it as insecure, even if their funds were never moved. On Tuesday, the team urged users to update to web wallet 4.26.4 or later, create a new wallet, and transfer funds to the new wallet as soon as possible, then avoid using the old wallet again.

In other words, the recovery program is intended to address already-compromised wallets, while the wallet update is meant to prevent the vulnerability from creating new points of exposure. That separation is important: recovering from the past doesn’t automatically secure future operations, especially for users who continue to reuse older wallet instances.

Qubic’s guidance effectively asks users to assume that wallet creation time matters. That can be a critical distinction for users who may have assumed that “no visible loss” meant a wallet was safe.

What to watch next

With the chain processing again and claims submissions underway, the key open questions are how recovery progresses at the protocol level and how quickly affected balances become retrievable via the reclaim workflow. Wallet holders should focus on upgrading and migrating to the post-fix web wallet, while others with exposure to Qubic should monitor the network’s stability and any follow-up updates from the project as the recovery period unfolds.