Sensitive data of India’s largest nuclear plant shared on dark web

A ransomware group has published thousands of files it claims are linked to India's largest nuclear power plant, raising concerns over the possible exposure of sensitive infrastructure data, Reuters reported.

The group, World Leaks, uploaded the files to the dark web, claiming they were obtained from the Reliance Group, one of the contractors involved in the Kudankulam Nuclear Power Plant in the southern state of Tamil Nadu.

The leaked material reportedly includes facility blueprints, supplier information, inspection records, meeting documents, equipment reviews and insurance papers dated between 2016 and mid-2025. The wire-service reviewed the documents but said it could not independently verify their authenticity.

Reliance Group acknowledged that one of its servers had suffered a "partial breach". In a statement to Reuters, the company said the affected server was hosted by third-party data centre provider Yotta and that the Indian government had been informed. It did not specify what information had been compromised.

Yotta said it detected suspicious activity on the server on May 29 and immediately blocked what it described as a suspected ransomware attack. However, it said Reliance Infrastructure later informed it that external threat actors had claimed responsibility for a data breach. The company said it had been unable to verify those claims but had shared the findings of its technical investigation with Reliance and was supporting the ongoing inquiry.

According to Reuters, around 19,000 of the leaked files appeared to contain the most sensitive information from a larger cache of more than 858,000 files allegedly stolen from Reliance.

A source familiar with the matter told Reuters that India's Nuclear Power Corporation is coordinating with Reliance over the incident, while the Indian Computer Emergency Response Team (CERT-In) is investigating the alleged breach.