Three Ukrainian drone strikes severely damaged Yandex data-center infrastructure between October 7 and 11, 2026. Yandex attributed the attacks to Ukrainian forces, though independent confirmation of responsibility has not been established in available reporting.
The Sasovo data center in Russia’s Ryazan region took the first hit during the night of October 7–8 and was shut down completely, according to Yandex. A second facility in Kaluga was struck on October 9, with part of its infrastructure disabled.
A third site in the Vladimir region was attacked on October 11 and taken offline. The outages disrupted Yandex Cloud services and affected other Russian online services that relied on Yandex infrastructure, according to reporting by The Moscow Times.
What “2.84% Lost” Actually Means
The data-loss figure applies only to customer data touched by the attacks, not to Yandex Cloud’s entire holdings.
Yandex said it restored access to 97.16% of customer data affected by the attacks. The remaining 2.84% could not be recovered because equipment was critically damaged and the customers in that group had no backup copies stored on the platform.
That 2.84% figure does not represent Yandex Cloud’s total data holdings. It covers only the portion of attacked data belonging to customers who had not activated backups before the strikes.
Customers who had used Yandex Cloud’s backup tools retained their data. Yandex said 100% of those customers’ backed-up data was preserved, a sharp contrast with the permanent losses suffered by customers who had stored no separate copies.
Supercomputers Among the Casualties
The attacks also took down three of Yandex’s supercomputers, though the full consequences for AI and research workloads remain unclear.
The Sasovo facility housed two of Yandex’s three supercomputers. According to an analytical report published by Ukraine’s Center for Political and Legal Reforms, Chervonenkis had a stated peak capacity of 29.42 petaflops and Lyapunov reached 20.03 petaflops.
The Vladimir site held Galushkin, rated at 20.64 petaflops by the same report. The analytical report links all three machines to their respective facilities, though available reporting does not fully detail the downstream effects on Yandex’s AI and research workloads.
Yandex Changes Its Backup Default
Yandex responded by making automatic backups the default for new virtual machines, a shift that reduces accidental exposure but does not guarantee recovery from large-scale physical attacks.
Before the attacks, customers had to activate Yandex Cloud backup tools manually. After the incident, Yandex made automatic backups the default setting when customers create new virtual machines, according to its statement. Users can still disable the feature through the management console.
The policy shift moves backup activation from a customer configuration task to a platform-level default. It is expected to reduce accidental exposure for new users who do not enable protection on their own.
Default backups do not guarantee recovery from a large-scale physical attack. Automatic backups remain subject to retention limits, shared infrastructure failures, and insufficient geographic separation from the primary system.
Russian Businesses Eye Exits
Some Russian businesses reportedly began exploring foreign data-center capacity after the strikes, with Kazakhstan cited as a preferred destination by industry sources.
Industry sources and market participants cited by Ukrainska Pravda said Russian companies began exploring foreign data-center capacity after the October attacks. Kazakhstan was identified as a particularly attractive destination by an industry executive and other market participants.
Some businesses reportedly reserved or explored capacity at facilities outside Russia to reduce exposure to further disruption. Those claims come from industry sources and do not confirm a large-scale or completed migration.
The strikes illustrate that cloud availability depends on physical buildings, power systems, networking hardware, and geographic separation, not software redundancy alone. Some affected customers without backups suffered permanent data loss, a consequence that cloud hosting alone could not prevent.
