On the night of October 17 to 18, an attacker emptied 1,404 Qubic wallets, or 2,940 billion QU. The response followed within hours: the Computors stopped the network, freezing 87.1% of the st
On the night of October 17 to 18, an attacker emptied 1,404 Qubic wallets, or 2,940 billion QU. The response followed within hours: the Computors stopped the network, freezing 87.1% of the stolen funds on site, and MEXC blocked in about an hour the account that had received the rest. Twelve days later, the network is running again, 293 billion QU have returned from the exchange to the chain, and the first verified owners have been reimbursed. The flaw did not come from the protocol but from seed generation on certain Apple devices, and it also concerns intact wallets.
A seed reconstruction attack, executed with perfectly ordinary signed transfers. According to the status report published by Qubic, some seeds had been generated with insufficient entropy during their creation on specific combinations of device and browser. An attacker was able to reproduce them, then sign valid transfers from 1,404 identities in less than two hours. No transaction was forged, and the core of the network was not affected: the flaw is at the wallet level, where the seed phrase is born, not in the consensus.
The amount, 2,940 billion QU, represented about 1.4 million dollars at the rate of October 18 (0.000000477 $ per QU according to CoinGecko), making it a modest value incident but wide in number of victims. The reaction was quick: the Computors, the 676 machines validating the ticks, coordinated a network stop at tick 85,371,949. No further transactions were processed, and 87.1% of the funds still present on eight addresses controlled by the attacker were frozen on site.
The remaining 12.9%, or 379 billion QU, had been sent in two transactions to a single deposit address at MEXC. The exchange froze the receiving account about an hour after the funds arrived, then suspended QUBIC deposits and withdrawals on October 18 at Qubic’s request. Bitget did the same the same day, citing “wallet maintenance.” Gate.io mentioned a “thorough technical review” before any resumption.
Mostly escrowed, and back on chain for the part that passed through MEXC. During the pause, the affected funds were placed in a protected escrow, according to Qubic. On October 20, the Computors quorum approved the recovery plan, the network resumed, and Qubic announced on X that “the Qubic network is live again,” specifying that the first funds had been returned to verified owners without disclosing the amount. A community vote had been organized beforehand, for consultation: the decision rested with the quorum, in accordance with network rules.
The follow-up can be verified on the explorer. On October 28 at 08:07 UTC, at tick 87,353,465, 293,039,994,345 QU returned to the address that had sent them to MEXC ten days earlier (transaction). This address now shows a zero balance, consistent with escrow status. The funds returned from the exchange join the same claims process, but the portal warns that this route is slower and depends on cooperation from authorities. If any remainder is missing on arrival, Qubic says it wants to cover it by a community contribution, to reimburse each affected user.
Date (UTC) Event Source Oct 17, 23:42 to Oct 18, 1:26 1,404 identities emptied, about 2,940 billion QU, via signed transfers Qubic Oct 18 around 1:52 MEXC freezes account that received 12.9% of funds Qubic, MEXC Oct 18 Network stopped at tick 85,371,949; MEXC and Bitget suspend deposits and withdrawals Qubic, exchange notices Oct 19 Web wallet 4.26.4: seed generation fixed Qubic Oct 20 Computors quorum approves recovery; network resumes; portal opens; first funds returned Qubic (X) Oct 28, 8:07 293.04 billion QU return from MEXC to frozen original address Qubic Explorer, tick 87,353,465 Oct 29 MEXC reopens withdrawals, then deposits at 2 p.m. Qubic (not confirmed by public MEXC notice) May 1, 2027 Claims window closes Official portalOn the market side, QUBIC lost about 19% between October 18 and 30, for a capitalization of about 57 million dollars (CoinGecko). It is impossible to isolate the incident’s share in this decline, which occurred on a market itself risk-averse.
Through the official portal, and only it:weak-seed-reclaim.qubic.org. The tool does not move any funds, it collects requests; each payment is decided and applied by the quorum. An address checker first allows knowing if an identity appears on the list of affected addresses, without signature or proof. The request itself is done in five steps.
Why proofs if you can sign? Because the attacker holds exactly the same key as the owner: a signature does not distinguish anyone. The portal classifies evidence by strength, from exchange withdrawal receipt to the affected address (strongest) to confirmation of an OTC deal, including a funding trail prior to the incident; a sworn statement is only accepted as support. Simple and undisputed cases go through a fast track, disputed, weak or large cases are reviewed by core developers.
The schedule is known. The first reimbursements, launched the week of October 26, target indisputable cases: identities published with signatures before the incident, OTCs confirmable by counterparties, known community project funds. Three follow-ups occur in December 2026, February 2027, and April 2027, the last covering all remaining valid claims.
Each approved request is publicly displayed (address and amount) for seven days before payment, and amounts come from the frozen chain snapshot, not the claimant’s input. Early filing brings no advantage; strong proof does. QEarn locks will return in later batches, and QX orders were canceled. According to Qubic, more than 230 requests had been received by late October.
Check the origin of their seed, and migrate to be safe. The fix in version 4.26.4 prevents creation of new weak seeds, it does not repair old ones. Qubic is explicit: a web wallet created before this version must be considered unsafe, “even if your funds were never touched“. The same applies to iOS app and iOS web wallet users, even if not on the list of affected addresses. Android app wallets were not reported and no mobile app updates were needed.
The portal also mentions a “pending” list for funds from weak but not emptied seeds, released after verification. If your identity appears there, the procedure is the same: new identity on an up-to-date wallet, then request on the portal. And a rule valid for all such incidents: the Qubic team never initiates private messages, never asks for a seed, and charges no recovery fees. Support is via a dedicated Discord channel, moderated; Qubic has no ticket system, limiting impersonations.
Two readings coexist, and both are founded. First: a network capable of stopping within hours on validator decision saved 87% of funds, where a chain without this leverage would have watched the total amount depart. We described the role of Computors and the useful proof-of-work; this episode shows the operational aspect. Second: this same leverage means 676 machines can freeze balances and rewrite a situation, which chain stop critics will note.
On the cause, Qubic keeps technical details until recovery ends, to avoid inspiring copies, and promises a full report. Security firm SlowMist published on October 20 an analysis suggesting the wallet’s seed generator relied on Math.random, a non-cryptographic function, whose outputs passed in clear in a network header; six consecutive values sufficed, in their proof of concept, to reconstruct the generator state. Qubic did not confirm this scenario, and its affected device list, focused on Safari and iOS, suggests a factor specific to these platforms.
This is also the second security incident this year: on July 13, Qubic’s GitHub organization was compromised via an access token, with no fund loss reported according to the post-mortem published the next day.
Upcoming deadlines are set: technical report at recovery end, first reimbursement update in December, Bitget and Gate.io resumption to announce, still suspended as of October 30 according to Qubic, and claim closure May 1, 2027. The open question is simple: how many of the 1,404 owners will provide proof the attacker does not own?
