Ukraine's military intelligence has claimed responsibility for a major cyberattack targeting one of Russia's newest nuclear submarines, the Knyaz Pozharsky, potentially exposing vulnerabilities in the Kremlin's naval deterrent, the Sunday Times reported on Sunday.
According to a statement by Ukraine's Defense Intelligence (DIU), hackers gained access to a wide range of classified materials related to the submarine, including detailed technical documentation, combat instructions, engineering reports, and crew rosters. The files also reportedly include a full operational schedule, outlining both combat and routine activities.
“The information obtained by the intelligence officers allows us to identify the features and technical limitations of not only the Knyaz Pozharsky, but also other submarines of the 955A project, which are critical to maintaining the imperial myth of the aggressor state of Russia,” the DIU said.
The Knyaz Pozharsky, which entered service in late July, is a Project 955A Borei-A class submarine — considered one of the most advanced platforms in Russia’s nuclear triad. It is stationed in Gadzhiyevo, in the Murmansk region, and is part of the Russian Navy’s Northern Fleet.
Each Borei-A class submarine is capable of carrying up to 16 R-30 Bulava intercontinental ballistic missiles, with each missile capable of delivering multiple nuclear warheads. The vessels are designed for high stealth, maneuverability, and significant strike capability.
Cyberattack is latest in series of Ukrainian intelligence operations
While the hacking claim could not be independently verified, it is the latest in a series of intelligence operations reportedly carried out by Ukraine against Russia’s strategic assets. In June, Ukraine launched “Operation Spider’s Web,” a large-scale drone strike targeting Russian airfields that destroyed several aircraft used in Russia’s nuclear force.
“Nuclear weapons are the main symbol of Russia’s global greatness,” Maxim Starchak, a nuclear policy analyst, wrote at the time. “Operation Spider’s Web was undoubtedly a blow to the Kremlin’s pride.”
The report on the submarine breach emerged on Sunday, as Russian and Chinese naval forces conducted joint anti-submarine drills in the Sea of Japan. The exercises are part of a scheduled cooperation initiative between the two countries.
The drill came shortly after US President Donald Trump ordered two American nuclear submarines to be deployed in “the appropriate regions” following remarks made by former Russian president Dmitry Medvedev.
No statement has been issued by the Russian government regarding the alleged breach, and no Western intelligence agencies or cybersecurity firms have confirmed Ukraine’s claims.
The cyber operation follows heightened rhetoric from Moscow over its nuclear capabilities throughout the war in Ukraine. While senior Russian officials have made repeated threats involving tactical nuclear weapons, no such arms have been used in the conflict.
Last month, Russian President Vladimir Putin reiterated the central role of the nuclear triad in safeguarding Russian sovereignty. Speaking at the commissioning ceremony of the Knyaz Pozharsky, he announced plans to build six more nuclear submarines by 2030, which would carry the Poseidon nuclear-powered underwater drone.
Russia has also expanded its military footprint in the Arctic, viewing the region as a strategic priority. The Kremlin has invested heavily in military infrastructure and energy exploration across the Arctic, capitalizing on newly accessible shipping lanes created by melting ice. These efforts have at times placed it in competition with China, which announced plans for an “Arctic Silk Road” in 2018.
The Northern Fleet, which operates the Borei-class submarines, regularly conducts under-ice patrols and Arctic combat exercises as part of its effort to maintain dominance in the region.
While the scope and impact of the reported Ukrainian hack remain unclear, the operation, if confirmed, would represent a significant blow to the secrecy and strategic credibility of one of Russia’s most powerful nuclear platforms.