Qubic restarts blockchain, opens recovery claims after $1.4M hack

Layer-1 blockchain Qubic has restarted its network and launched a recovery process after a wallet seed vulnerability allowed an attacker to drain roughly $1.4 million in QU tokens from 1,404 accounts, according to the project’s latest update.

Qubic’s blockchain explorer shows the network resumed processing ticks 8:00 pm on Oct. 19, advancing beyond tick 85,371,949, where it was halted on Sunday.

Qubic said its network validators, known as Computors, had approved a recovery plan and that the project had launched a claims platform for affected wallet holders.

Affected users can check their address and submit a claim through Qubic’s reclaim platform. Affected users have until May 1, 2027, to submit claims, according to Qubic.

The network was halted Sunday to prevent further movement of stolen funds after attackers exploited predictable wallet seeds generated by vulnerable wallet software.

The vulnerability affected wallet seeds generated using Qubic’s web wallet on certain Apple devices and browsers, where an insecure random-number generator could produce predictable seeds. Qubic on Sunday said it had fixed the seed-generation flaw in the latest version of its web wallet. 

“If you created your wallet with the Qubic web wallet before version 4.26.4 (released 19 October), treat it as insecure, even if your funds were never touched,” said Qubic on Tuesday.

“Update to web wallet 4.26.4 or later, then create a new wallet,” said the team. “Move your funds to the new wallet as soon as you can, and never use the old one again.”

Related: Qubic freezes chain after attacker drains 1.4K wallets with weak seeds