Rosstat breach: hackers publish data on Russia's losses in the war with Ukraine

Hacker statement and discrepancy in figures

The hacker groups Kiberpartizany BY and Silent Crow have claimed a large-scale breach of Russia's Rosstat: according to them, about 23 terabytes of data were stolen, including internal documents, demographic and economic statistics, as well as information on losses in the war against Ukraine. Based on this data, the groups made their own calculations of the number of deaths since the start of the full-scale invasion in February 2022. According to Kiberpartizany BY, as of August 27, 2026, at least 393,881 Russian citizens had been killed; Silent Crow cites a higher figure — 450,100 dead. The difference is explained by different methodologies: Kiberpartizany BY counted deaths where the cause was listed as combat operations or their consequences, while Silent Crow additionally included non-combat losses among servicemen, deaths marked as terrorist attacks, and deaths of people registered in Russia who died in occupied territories or in Ukraine without an established cause.

Why the figures matter and how they compare with previous estimates

Russia has not published official combat casualty statistics since September 2022, and since 2024 Rosstat stopped publishing annual data on causes of death, which has made it difficult to independently assess the demographic consequences of the war. For comparison: as of November 8, the joint database of BBC News Russian Service and Mediazona, which compiles a list of killed Russian soldiers by name, contained about 286,000 names — and the list is known to be incomplete, especially for the last months of the war. A joint study by Meduza and Mediazona based on analysis of inheritance registry data estimated the number of killed Russian soldiers at the end of 2025 at approximately 350,000. Thus, the hackers' estimates are consistent with previously published independent studies, although this does not yet prove the accuracy of each individual number.

Verifying authenticity and limitations of the data

Meduza and Mediazona reported that they gained access to the data published by the hackers and began verifying it. The journalists intend to establish not only the authenticity of the materials but also their completeness — in particular, to rule out the possibility of deliberate falsification. There are other limitations as well: causes of death in medical documents do not always reflect the actual circumstances of death, and Rosstat's internal databases do not contain up-to-date data on those missing in action, who may be declared dead only after a long time. Therefore, even data from the state statistical agency does not automatically yield a definitive figure for military losses. If the authenticity and completeness of the leak are confirmed, these materials could become one of the largest sources of information on the demographic consequences of the war for Russia.