Attack on 8.7 million CPR numbers was created by artificial intelligence

An alleged hacker says artificial intelligence wrote the computer program that was used to pull 8,749,975 CPR numbers out of Denmark's CPR register. The claim comes from the same source who last week shared the leaked data with the newspaper Politiken. The source has now also handed over the source code of the program said to have been used in the attack.

The method described is "vibecoding", where a person relies on an AI tool to generate software. According to the hacker, the program systematically and illegally retrieved the numbers from the register. The article's headline and standfirst say that experts see this as a major security problem created by artificial intelligence.

Politiken does not know the hacker's identity. The paper interviewed the source in writing, in English, over an encrypted service. The account of how the attack was carried out therefore rests on the source's own statements, and the code is described as the program "allegedly" used in the attack.

The piece is by Lars Igum Rasmussen, Jonas Pröschold and Sebastian Stryhn Kjeldtoft, and it was published on 12 October 2026. It frames the leak of roughly 8.7 million CPR numbers as a historic data breach in Denmark. It also raises the concern that AI tools can help people build programs capable of large-scale data theft. The text available here is only the opening of the article, so the experts' specific arguments and further details of the code are not included.