Layer-1 blockchain Qubic froze its network on Sunday after an attacker exploited weakly generated wallet seeds to drain roughly $1.4 million from more than 1,400 accounts, the project said in a statement on X. The chain stopped at tick 85,371,949 and remains paused.

The attacker made off with 2.94 trillion Qubit (QU). Qubic said 87.1% of the drained funds never left the network and sit frozen in place. The remaining 12.9% went to exchange MEXC, whose team froze the receiving account within about an hour.

"87.1% of the drained funds never left the Qubic network and remain frozen in place," Qubic said. "The remaining 12.9% was sent to MEXC, whose team froze the receiving account within about an hour."

Which wallets were exposed?

The vulnerability hit wallets whose seeds were generated in specific environments:

• Any browser on an iPhone or iPad
• Safari on a Mac until Oct. 18, 2026
• The Qubic iOS app before July 2025

Qubic has fixed the seed-generation flaw in the latest version of its web wallet. A GitHub commit for version 4.26.4 shows the team replaced JavaScript's Math.random() — a function unsuitable for cryptographic secrets — with the cryptographically secure crypto.getRandomValues() when creating wallet seeds.

The operational consequence is a full network halt with no announced restart date. Qubic's core team is identifying affected wallets and preparing recovery options for a vote by the network's Computors, the validator set that will decide what happens to the frozen funds. The team said it will publish a full technical report once a recovery plan is settled.

Qubic did not immediately respond to a request for comment from Cointelegraph.

Another case in a known failure pattern

The Qubic theft joins a string of attacks tied to weak seed generation. In July, Coldcard disclosed that attackers stole funds from wallets whose seeds had been weakened by a firmware bug. Similar flaws affected Trust Wallet's browser extension and the Libbitcoin Explorer tool in 2023.

The broader loss picture is worsening. Hacks and exploits accounted for 19% of crypto crime cases but 40% of reported losses in the third quarter, according to AMLBot's 2026 investigations report, which covered 250 investigations opened since the start of the year. Related coverage from Cointelegraph notes Bitget's $388 million hack pushed Q3 crypto security losses past $1 billion.

Qubic is a feeless layer-1 supporting transactions and smart contracts, built on Useful Proof of Work (UPoW), a consensus mechanism that repurposes mining energy to train artificial intelligence. Its token held a market capitalization of about $62.6 million at the time of writing, according to CoinGecko.

The chain stays down until the Computors vote on a recovery plan — the next structural decision point for the project.