A hacker has allegedly stolen a vast cache of sensitive data, including highly classified defence documents and missile schematics, from a state-run Chinese supercomputer, in what could amount to the largest known data breach in China.

The dataset, said to contain more than 10 petabytes of sensitive information, is believed by experts to have been extracted from the National Supercomputing Center in Tianjin, according to CNN.

The facility serves as a centralised infrastructure hub for over 6,000 clients nationwide, including advanced scientific institutions and defence agencies.

Cybersecurity experts who have communicated with the suspected hacker and examined samples of the data shared online say the individual appeared to access the supercomputer with relative ease, extracting vast quantities of information over several months without detection.

An account identifying itself as FlamingChina published a sample of the alleged dataset on an anonymous Telegram channel on February 6, claiming it included “research across various fields, including aerospace engineering, military research, bioinformatics, fusion simulation and more.”

The group further alleged that the material was connected to “top organizations” such as the Aviation Industry Corporation of China, the Commercial Aircraft Corporation of China, and the National University of Defense Technology.

Cybersecurity experts who have examined the material say the group is offering a limited preview of the alleged dataset for several thousand dollars, while full access is being advertised for hundreds of thousands of dollars.

Payment is reportedly being sought in cryptocurrency.