Coldcard Hackers Launder Stolen BTC and ETH via Mixers Amid Growing Losses

Woofun AI reports that cryptocurrency mixing protocols have become the primary laundering vector for funds stolen in the ongoing Coldcard exploit, a complex security failure that has elevated the incident to the status of the third-largest hack of 2026. Blockchain security platform CertiK identified the movement of significant digital assets into obfuscation services, while industry observers including Cointelegraph noted the involvement of multiple threat actors leveraging established privacy tools such as Wasabi and Tornado Cash to sever the on-chain trail. This coordinated effort to anonymize illicit proceeds highlights the evolving sophistication of attackers targeting hardware wallet vulnerabilities, transforming a static firmware defect into a dynamic financial crisis for thousands of users.

Monitored by Woofun AI, the specific laundering mechanics reveal a deliberate two-stage process designed to obscure the origin of the stolen capital. On Tuesday, approximately 64 Bitcoin, valued at $4.17 million, was transferred from the address bc1q0 to the Wasabi mixing protocol, a move highlighted in an X post by CertiK. The following day, Wednesday, saw the transfer of 200 Ether, worth roughly $380,000, into Tornado Cash.

These protocols operate by pooling cryptocurrency from numerous users and scrambling the transaction history, effectively breaking the publicly traceable link between senders and recipients. This structural opacity significantly hinders forensic analysis, thereby decreasing the probability of asset recovery for victims. A CertiK spokesperson suggested to Cointelegraph that the activity might stem from a "smaller exploiter" or "copycats" following the initial breach, indicating a fragmented but persistent threat landscape.

Structurally, the laundering patterns observed in the Coldcard case mirror those of previous major exploits, underscoring a recurring reliance on specific privacy infrastructure. In April, the hacker responsible for the $293 million Kelp DAO hack laundered approximately 75,700 Ether, which was valued at $175 million at the time, primarily through THORChain. This operation generated about $910,000 in fee revenue for the protocol, demonstrating the economic incentives for using such services.

Additionally, the Kelp DAO attacker utilized the Umbra privacy protocol to further complicate tracing efforts. The parallel use of mixing and privacy tools in both incidents suggests that attackers are increasingly standardized in their post-exploit behavior, leveraging known vulnerabilities in privacy-preserving technologies to maximize the longevity and usability of stolen funds.

The scale of the Coldcard exploit itself is staggering, with Galaxy Digital reporting that at least $100 million in Bitcoin has been drained across three confirmed attack waves from 7,300 victim wallets. The firm also identified a suspected fourth wave, which could push total losses to approximately $130 million in BTC. On-chain tracing by TRM Labs indicated that the majority of victim funds remain pooled in a small number of attacker-controlled addresses, with limited mixing attempts thus far.

However, TRM Labs noted that "differences in transaction construction" across the attack waves suggest the involvement of multiple distinct entities. This aligns with Galaxy’s earlier findings that at least 15 different attackers have exploited the Coldcard vulnerability, pointing to a widespread and coordinated campaign rather than a single isolated incident.

The technical root cause of this widespread compromise traces back to a firmware bug from March 2021, which weakened seed randomness on certain Coldcard wallets. This defect reduced key strength from 128 bits to just 40 bits, rendering the wallets "brute-forceable without physical access," according to TRM Labs. Dragonfly managing partner Haseeb Qureshi commented that roughly "$2 of AI hardening" could have prevented the exploit, citing reports that some AI models rediscovered the vulnerability in less than 20 minutes. This disparity between the low cost of prevention and the massive financial impact underscores a critical failure in security auditing and proactive risk management within the hardware wallet sector.