Ukrainian drones struck Yandex’s massive data center in the town of Sasovo in Russia’s Ryazan region, setting off a major fire that forced the company to shut the site down and triggered outages across large swaths of the Russian internet. Russian and international reports describe the attack as the first major strike specifically targeting Russia’s data infrastructure since the full-scale invasion of Ukraine began in 2022, underscoring how digital backbones and cloud platforms have now become front-line targets in the war.
The Sasovo hub is one of Yandex’s five large data centers and hosts tens of thousands of servers, including two of the company’s three flagship AI supercomputers, codenamed Chervonenkis and Lyapunov. Both systems are built around Nvidia A100 accelerators and were central to training Yandex’s in-house large language models, including YandexGPT, which powers many of the company’s generative AI services and chatbots. Chervonenkis, the most powerful of the trio, once ranked 19th on the Top500 list in 2021 with 21.53 FP64 petaflops of performance, though it has since slid to around 101st as global systems have leapfrogged it. A third supercomputer, Galushkin, is housed separately in Vladimir and is not believed to have been directly affected by the Sasovo strike.
Yandex has said the data center’s operations are “completely halted” and that emergency teams are still working at the site, while the company assesses whether any of the high-end equipment can be salvaged. Reuters reports that Yandex cannot yet determine whether key hardware at the facility is restorable, a worrying admission given the scale of the blaze seen in videos and local accounts. Meduza and Tom’s Hardware note that, given the intensity of the fire and the need to cut power to the entire complex, the odds that Chervonenkis and Lyapunov survived intact are considered low. Western export controls already prevent Russia from legally acquiring or upgrading most advanced AI accelerators like the A100, meaning that if these systems are destroyed, rebuilding equivalent supercomputing capacity with similar hardware would be extraordinarily difficult. Analysts cited in Ukrainian coverage suggest Yandex may be pushed to rely more heavily on Chinese-made accelerators and cloud infrastructure for future model training, which could reshape Russia’s AI stack overnight.
The immediate fallout has been felt across Yandex Cloud and the broader Russian web, even as the company insists that its headline consumer services remain mostly available. Users and monitoring services have reported issues with Yandex Mail, Disk, Documents, Pay, and Market, along with degraded performance or outright downtime for numerous third-party platforms that lean on Yandex Cloud. According to Meduza and regional tech watchers, services affected include real estate platform Cian, ebook marketplace Litmarket, Russian Railways systems, Spartak Moscow’s digital infrastructure, crypto exchange Rapira, Astral, and business software from 1C, as well as corporate systems at T-Bank, Ozon, and Wildberries. A bus operator in the Moscow region suspended online ticket sales, while watchdog Detector404 logged more than 58,000 complaints over 24 hours tied to outages and performance issues, painting a picture of a country-level internet wobble radiating out from a single cloud hub. Several Russian media outlets, including major state-aligned platforms like RIA Novosti, Vesti, and Interfax, also experienced downtime after what RBC described as an attack on their “infrastructure partner,” highlighting how deeply Yandex is wired into the information ecosystem often dubbed “Russia’s Google.”
The strike also hit the grounds of the Sasta machine-tool plant, an industrial facility whose buildings Yandex repurposed in 2014 to house the Sasovo data center. Sasta manufactures specialized machine tools supplied to a range of Russian industrial and defense-related enterprises and is itself subject to Western sanctions, making the complex a hybrid target where military-adjacent manufacturing and high-value digital infrastructure sit side by side. Local authorities initially described the incident as a fire at an industrial site, and Meduza notes that it remains unclear whether Ukraine’s primary intended target was Sasta’s production capabilities or Yandex’s computing infrastructure. Regardless, the attack fits into Kyiv’s broader strategy of hitting sanctioned defense-industry nodes and high-impact economic assets, a campaign some Ukrainian outlets argue has in practice bitten harder than portions of the West’s formal sanctions regime.
This digital counterstrike comes just weeks after Russia ramped up its own campaign against Ukrainian telecommunications and data centers, including attacks on facilities used by major Ukrainian internet providers and cloud operators. The BBC has reported that Russian forces recently targeted sites like Datagroup’s data center, which Moscow claimed was used by Ukrainian military intelligence, and Meduza tallies at least eight Ukrainian data centers damaged or destroyed in strikes since late September. By striking Sasovo, Ukraine has signaled that Russia’s AI and cloud infrastructure—once considered back-office tech—now sits firmly within the battlespace, with generative models, recommendation engines, and supercomputers treated as strategic assets alongside tanks and artillery. For the global tech and AI community, the incident is a stark reminder that the hardware behind large language models and cloud gaming servers is not abstract: it lives in physical buildings, can be cut off by sanctions, and, as this week proved, can be directly targeted in modern warfare.
