Hacker groups claim to have breached Russia’s Federal State Statistics Service (Rosstat) and obtained data they used to calculate estimates of between 393,000 and 450,000 Russian citizens killed since the start of the full-scale invasion of Ukraine in February 2022. The estimates from Cyberpartisans BY and Silent Crow are broadly consistent with previous independent estimates of Russian military losses.
The hacker groups Kiberpartizany BY and Silent Crow say they stole about 23 terabytes of data from Rosstat, including internal documents, demographic and economic statistics, and information on Russian losses in the war against Ukraine. The data enabled their own calculations of the number of people killed since the start of the full-scale invasion in February 2022.
According to Kiberpartizany BY, as of 27 August 2026 at least 393,881 Russian citizens have been killed in the war. Silent Crow gives an even higher figure of 450,100 dead. The significant difference is due to different counting methods: Kiberpartizany BY counted deaths where military action or its consequences were listed as the cause, while Silent Crow added non-combat military losses, deaths marked as terrorist acts, and deaths of people registered in Russia who died in occupied territories or in Ukraine where the exact cause was not established.
Russia has not released official statistics on combat losses since September 2022. From 2024, Rosstat stopped publishing annual data on causes of death, making independent assessment of the war's demographic impact much more difficult. Access to the agency's internal statistical materials may enable a more accurate assessment of human losses.
For comparison, as of 8 November, the joint database of BBC News Russian Service and Mediazona, which collects a list of dead Russian servicemen identified by name, contained around 286,000 names, though it is known to be incomplete, especially for recent months. A joint study by Meduza and Mediazona, based on inheritance registry analysis, estimated about 350,000 fallen Russian servicemen by the end of 2025.
The hackers' estimates align with figures from previously published independent studies, though this does not yet prove the accuracy of each individual number. Meduza and Mediazona have said they obtained access to the published data and have begun checking its authenticity and completeness. They also need to rule out the possibility of deliberate data falsification.
Causes of death in medical documents do not always reflect the actual circumstances of a person's death, and Rosstat's internal databases do not contain up-to-date information on people listed as missing, who may be declared dead only after a long period. Therefore, even data from the state statistics agency cannot automatically provide a definitive figure for Russian military losses. If the authenticity and completeness of the leak are confirmed, the materials could become one of the largest sources of information on the war's demographic consequences for Russia.
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Estimated Russian deaths in Ukraine war by source
deaths
Source: BBC News Russian Service, Mediazona, Meduza, Kiberpartizany BY, Silent Crow via Bloomberg and Eurone
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Analysis
Why This Matters
Provides the first large-scale internal Russian data on war losses since official statistics were suppressed in 2022
Could enable more accurate independent assessments of the war's demographic toll on Russia
If verified, the leaked data may offer one of the most comprehensive pictures of casualties to date
Background
Russia’s full-scale invasion of Ukraine began in February 2022. The Russian government stopped publishing official combat loss figures in September 2022, and from 2024 ceased releasing annual cause-of-death data, making independent verification of casualties difficult. Hacker groups have periodically targeted Russian state agencies, but this breach of the federal statistics service is among the largest claimed.
Key Perspectives
Kiberpartizany BY: Assess that at least 393,881 Russian citizens have been killed, counting only deaths where military action or its consequences were listed as the cause.
Silent Crow: Estimates 450,100 dead, using a broader definition that includes non-combat military losses, deaths marked as terrorist acts, and deaths in occupied territories or Ukraine where the exact cause was not established.
BBC News Russian Service and Mediazona: Their joint database, based on identified names, has around 286,000 entries, though it is known to be incomplete.
Meduza and Mediazona: Their inheritance-registry study estimated roughly 350,000 fallen Russian servicemen by the end of 2025, consistent with the new figures.
What to Watch
Verification by Meduza and Mediazona of whether the leaked data is authentic and complete, and whether it was deliberately falsified
Whether Rosstat or the Russian government respond to the breach or the published figures
Any subsequent independent analyses using the leaked data to refine casualty estimates
12 claims in this story checked against 1 source: 12 supported.
Show each claim
SupportedHacker groups say Rosstat data suggests more than 390,000 Russian deaths in the Ukraine war.Euronews: “Rosstat hack: data obtained suggests over 390,000 Russian deaths in Ukraine war.”
SupportedThe groups say they used data they claim came from Rosstat to estimate Russian war deaths.Euronews: “Hacker groups Cyberpartisans BY and Silent Crow say they hacked Rosstat and counted Russian losses since the invasion of Ukraine.”
SupportedThe groups claim to have stolen about 23 terabytes of Rosstat data, including internal documents and demographic and economic statistics.Euronews: “According to the hackers, they managed to steal about 23 terabytes of data, including internal documents, demographic and economic statistics, as well as information on Russian losses in the war against Ukraine.”
SupportedKiberpartizany BY says at least 393,881 Russian citizens had been killed in the war as of 27 August 2026.Euronews: “According to Kiberpartizany BY, as of 27 August 2026 at least 393,881 Russian citizens have been killed in the war.”
SupportedSilent Crow estimates 450,100 dead.Euronews: “Silent Crow gives an even higher figure of 450,100 dead.”
SupportedThe groups' estimates are broadly consistent with previous independent estimates, but that does not establish the accuracy of each number.Euronews: “In this way, the hackers' estimates are in line with figures from previously published independent studies, although this does not yet prove the accuracy of each individual number.”
SupportedKiberpartizany BY counted deaths attributed to military action or its consequences; Silent Crow also included specified non-combat and other deaths.Euronews: “Kiberpartizany BY counted deaths in which military action or its consequences were listed as the cause. Silent Crow, by contrast, not only included those killed in combat, but also added several other categories of deaths: non-combat losses among military personnel, deaths marked as terrorist acts”
SupportedRussia has not released official statistics on combat losses since September 2022.Euronews: “Russia has not released official statistics on combat losses since September 2022.”
SupportedRosstat stopped publishing annual causes-of-death data from 2024, making independent assessment of the war's demographic impact more difficult.Euronews: “from 2024 Rosstat stopped publishing annual data on causes of death, which has made an independent assessment of the demographic impact of the war much more difficult.”
SupportedThe BBC News Russian Service and Mediazona database contained around 286,000 identified names as of 8 November and was known to be incomplete, especially for recent months.Euronews: “as of 8 November the joint database of BBC News Russian Service and Mediazona, which collects a list of dead Russian servicemen identified by name, contained around 286,000 names. However, this list is known to be incomplete, especially for the most recent months of the war.”
SupportedA joint Meduza and Mediazona study estimated about 350,000 fallen Russian servicemen by the end of 2025.Euronews: “In a joint study by Meduza and Mediazona, based on analysis of inheritance registry data, the number of fallen Russian servicemen by the end of 2025 was estimated at roughly 350,000.”
SupportedMeduza and Mediazona say they obtained access to the hackers' published data and have begun checking its authenticity and completeness.Euronews: “Meduza and Mediazona have said they obtained access to the data published by the hackers and have begun checking it. The journalists aim to establish not only whether the materials are authentic, but also how complete the information is they contain.”