A cyberattack targeting data associated with the Kudankulam Nuclear Power Plant (KKNPP) has raised fresh concerns over the cybersecurity of India's critical infrastructure after ransomware group World Leaks claimed it had uploaded a massive cache of sensitive files to the dark web.

According to a Reuters report, the hacking group says it possesses more than 858,000 files allegedly linked to Reliance Group, one of the contractors associated with the nuclear power project. Of these, around 19,000 files were presented as particularly sensitive and reportedly include engineering drawings, supplier information, inspection records, equipment assessments and insurance-related documents.

Reuters said it reviewed a sample of the files, which were dated between 2016 and mid-2025, but could not independently verify their authenticity.

Reliance Group confirms partial data breach

Responding to the claims, Anil Ambani-led Reliance Group confirmed that it had experienced a partial data breach involving a server hosted by Yotta, an Indian third-party data centre service provider.

In a statement cited by Reuters, the company said the matter had been reported to the government and that appropriate authorities had been informed. However, Reliance did not disclose what specific information may have been compromised or whether any data related to the Kudankulam project had been exposed.

The Kudankulam Nuclear Power Plant, located in Tamil Nadu, is India's largest operational nuclear power station and plays a key role in the country's plans to significantly expand nuclear energy generation over the coming years.

If the leaked documents are genuine, cybersecurity experts say the exposure of infrastructure layouts, technical documents and supplier information could pose potential security concerns.

What was allegedly leaked?

According to the Reuters report, the files posted by World Leaks are claimed to include:

  • Engineering blueprints of certain facilities
  • Supplier and contractor details
  • Meeting and inspection records
  • Equipment review documents
  • Insurance-related paperwork
  • Other project records spanning nearly a decade.