Reliance Group Files Linked to Kudankulam Nuclear Plant Leaked On Dark Web

A ransomware group called World Leaks has published a massive trove of documents linked to India's Kudankulam Nuclear Power Plant on the dark web, Reuters reported, raising fresh questions about cybersecurity at the facility central to India's nuclear expansion ambitions.

Kudankulam, situated in Tamil Nadu, is the largest of India's seven operating nuclear stations and figures prominently in Prime Minister Narendra Modi's push to scale up the country's atomic power output.

The leaked material reportedly includes plant blueprints and vendor information tied to project contractor Reliance Group. Reliance Group, controlled by businessman Anil Ambani and one of the plant's contractors, acknowledged that a "partial breach" had occurred, Reuters reported.

The breach happened on a server managed by outside data-centre operator Yotta. The company said it has flagged the matter to authorities but has not specified which categories of data were exposed.

Scale of the leak

The leaked material spans 2016 through mid-2025, though it was unable to independently confirm the documents were genuine. Around 19,000 of the files were flagged as the most sensitive portion of a much larger set — roughly 858,000 documents belonging to Reliance that surfaced on the World Leaks platform.

The exposure centers on Reliance Infrastructure's work as the builder for Units 3 and 4 of the plant, a contract secured in 2018. Both units remain under construction and are slated to come online by 2027, together adding 2,000 megawatts of capacity.

What the documents reportedly contain

According to Reuters' review, the leak does not touch the reactors' core technology, which comes from Russia's state nuclear firm Rosatom. Instead, the exposed files reportedly cover ventilation and cooling systems for the two under-construction units, plans of a shared control room, approved-vendor lists, and notes from a 2024 equipment inspection conducted jointly by Reliance and the Nuclear Power Corporation. One document also allegedly details a terrorism-linked insurance policy worth $112 million covering the two units.

Nickolas Roth, a senior director at the Nuclear Threat Initiative, told Reuters the breach carries "serious" implications for plant security, since such records could let a bad actor trace which systems connect to which access points across the facility.

A pattern of vulnerability

Reuters noted this is not the first cybersecurity scare at Kudankulam — malware traced to a North Korean hacking group was discovered on the plant's administrative network back in 2019, though officials said at the time that operational systems were unaffected.

The wire service also cited cybersecurity firm Surfshark's data placing India third worldwide for data breaches, with 28.9 million compromised accounts last year, trailing only the US and France. A separate industry survey by the Data Security Council of India and Seqrite found most Indian organizations polled were either unaware of past attacks or lacked basic protective practices.