Why Bitcoin holders are the sharp end
Bitcoin security advocate Jameson Lopp warned that the breach was particularly concerning in France, which he described as the leading country for “wrench attacks,” noting that the leaked dataset included 26,805 people earning more than €100,000 and 386 earning more than €1 million. Lopp had already raised concerns about France’s crypto-targeting problem in January 2026, when he commented on a separate case involving a French tax official allegedly using privileged access to identify cryptocurrency owners. Now, a DGFiP breach has exposed detailed taxpayer information. The two incidents should not be portrayed as connected, but the security concern is clearly related.
CertiK’s data corroborates Lopp’s statement. The blockchain security company recorded 52 cases of verified wrench attacks globally in the first half of 2026, of which 33 took place in France. As such, France represents 63.5% of CertiK’s dataset, making it the largest national hub. According to CertiK, factors leading to the high concentration of wrench attacks in France include the country’s sizable crypto industry, notorious business leaders, publicly displayed extravagance, and the incidence of sensitive data breaches.
Because of this, the leak is bigger than just a privacy violation. A comprehensive database can help criminals skip the reconnaissance that they would need to do on their own: names tell them whom they are dealing with, an address reveals to them where to look, and the income information lets them know whether the target is worth pursuing.
CertiK refers to this process as “data-driven targeting“, and it means combining leaked information with social media, blockchain activity, and public information.
France has learned what it means to experience a transition of crypto-crime from the digital sphere into physical reality. Cybermalveillance.gouv.fr has reported on fraudsters who pretend to be employees of crypto platforms, banking fraud teams, and law enforcement bodies to convince people to remit funds or give away sensitive data. Law enforcement agencies have faced cases of threats, physical abuse, and abductions.
However, just having security features in place is not enough. Holders of high-value assets can reduce their exposure by avoiding publicly disclosing personal details, splitting important funds among various wallets, using multiple signatures, and storing sensitive recovery data in secure places. Any person whose information may have been involved in a breach must expect that any future fraud attempt will involve accurate details about them and, thus, can be very convincing.
A pattern regulators are chasing
The breach comes as France faces wider data-security problems. CNIL, France’s data protection authority, has made cybersecurity a major enforcement priority for 2026.
However, regulatory measures cannot erase any information after it has already been duplicated and sold. This is particularly important for users of cryptocurrencies because once cryptocurrencies have been transacted, there is no turning back.
ADAN reports that about 11% of people in France own cryptocurrencies, which represents a huge group of possible victims.
The leak does not imply that all holders of cryptocurrency in France face a physical risk or that hackers will use the information to carry out a direct attack. But CertiK’s statistics explain why the leak is quite sensitive.
With respect to the taxpayers who may be impacted by the breach, their best alternative would be to exhibit scepticism towards any unexpected phone calls, e-mail messages and texts, regardless of how much personal information the sender may have. Never give out any passwords, recovery phrases or private keys, and open the website or app of the relevant organization, not using the links or contact information from the unsolicited message.
The lesson is simple: personal data is part of the attack surface. In crypto, where trust can be the final barrier before an irreversible transaction, stolen information can become the tool that makes a scam believable — or helps a criminal decide whom to target.
