Russia’s Federal State Statistics Service (Rosstat) has confirmed a series of cyberattacks against its information systems, while two hacking groups claim to have stolen approximately 23 TB of data, including records relating to Russian military losses in Ukraine. Rosstat acknowledges that its websites were attacked but denies that its databases or protected information were compromised. The attacks took place between 29 October and 1 November 2026, affecting the agency’s central website and regional portals. Russian newspaper Kommersant reported that the websites had been defaced with messages in Belarusian and the logos of the Belarusian CyberPartisans and Silent Crow hacking groups. One message warned that nobody would escape accountability. The affected websites experienced periods of unavailability, although some services were subsequently restored. Rosstat cyberattack targets internal infrastructure The two groups claim to have penetrated Rosstat’s internal network, gaining access to databases, servers, virtualisation infrastructure, document management systems and employee computers. In its published account of the operation , CyberPartisans claims that it first entered the network approximately six months earlier and subsequently extracted more than 10 TB of information. Silent Crow has separately claimed that approximately 23 TB was obtained and that the attackers accessed some 25,000 computers across the agency’s central and regional operations. The groups also claim to have destroyed critical infrastructure, including virtual and physical servers, storage systems and applications used to process statistical information. Neither the extent of the alleged destruction nor the volume of stolen data has been independently established. Claims of stolen Russian casualty statistics Among the allegedly compromised records are demographic and economic statistics, population census materials, internal correspondence and information concerning Russian military casualties in Ukraine. Rosstat’s statistical methodology includes deaths resulting from military operations, although the agency stopped publishing annual cause-of-death statistics in 2024. If the hackers obtained unpublished mortality records, the information could potentially provide additional evidence about the human cost of the war. However, the casualty figures circulated alongside the attack have not been authenticated. CyberPartisans states that it placed Ukrainian statistics on Russian military losses on the defaced Rosstat website. Those figures should not be mistaken for independently verified records extracted from Rosstat’s internal databases. Rosstat denies database compromise In a statement reported by RBC , Rosstat described the attacks as carefully prepared and coordinated across multiple areas of its IT infrastructure. It said its monitoring systems had detected suspicious activity early enough to initiate a response. The agency maintains that no database compromise or leakage of legally protected information has been identified. Its security teams are investigating how the attacks were conducted, while strengthening access controls, monitoring and infrastructure protection. The confirmed website defacement does not itself establish that attackers gained access to internal databases or successfully extracted information. A similar distinction between unauthorised access and verified data theft arose in recent eeNews Europe reporting on the ConnectWise supply-chain attack . CyberPartisans and Silent Crow previously claimed responsibility for a July 2025 cyberattack against Russian airline Aeroflot that disrupted its IT systems and forced flight cancellations. The groups have indicated that they intend to release further information about the Rosstat operation, potentially providing an opportunity to assess their latest claims. The post Rosstat cyberattack: hackers claim 23 TB data theft appeared first on eeNews Europe .