Ukrainian drones damaged a Yandex data center in Russia’s Kaluga region early on October 9, knocking out several modules at the facility, the company confirmed. It was the second strike on Yandex infrastructure in two days, following an overnight attack on October 8 that started a fire at its data center in Sasovo, Ryazan region, about 580 kilometers from Ukraine. No employees were reported injured at either site.
In statements carried by Russian media, including Vedomosti and Tass, Yandex said several modules at the Kaluga facility had been completely disabled and that specialists were still assessing whether damaged equipment could be restored. The company did not commit to a timeline.
“Data centers are the iron heart of Yandex. Their operational capability is critical for the services that have become part of people’s daily lives,” the company said in a statement to Russian outlets. “We are continuing to assess the condition of the infrastructure, but it is currently very difficult to specify a timeline for restoring operations at the data centers.”
Kaluga governor Vladislav Shapsha said drones had attacked the regional capital and several municipal districts overnight, injuring nine people across the region, separate from the damage suffered at the data center itself.
The first strike, in Sasovo
The October 8 attack hit the town of Sasovo in Ryazan Oblast, southeast of Moscow, where a fire broke out at a Yandex data center after a drone strike. Yandex told CNBC that the facility had stopped operating entirely and that some of its services might be unavailable to users. “There are no casualties, and emergency services are on site dealing with the aftermath,” the company said at the time.
Russian outlet Astra reported, citing Wikimapia data, that the data center sits on the grounds of Sasta, a sanctioned machine-tool plant that appears on Russia’s register of defense-industry companies. Sasta makes computer-controlled machine tools, including five-axis machining centers, and has previously supplied the Tactical Missiles Corporation and Roscosmos. Ukrainian monitoring channels suggested the plant, not the data center alone, may have been the intended target, since the machines it builds cut precision parts used further up the arms supply chain.
Ryazan Oblast governor Pavel Malkov said two drones had been downed and that a roof fire and broken windows had damaged homes in the Sasovo district. Satellite imagery from Planet Labs later showed roof damage and fire signs on the data center building, according to Ukrainian outlets that reviewed the images.
Ukrainian outlet ZN.ua, citing the monitoring channel Exilenova+, reported that the power failure took down a broad range of Yandex Cloud infrastructure, including computing capacity, networking, data storage, databases, Kubernetes services, cloud AI platform capacity, and security and monitoring systems.
Why the target matters
Yandex is Russia’s largest technology company. Its search engine is often described as the country’s answer to Google, and Yandex Cloud hosts workloads for banks, retailers, developers, and businesses across the region. Until this week, Ukraine’s drone campaign inside Russia had focused on refineries, air bases, ammunition depots, oil terminals, and logistics networks. A data center, specifically one belonging to a consumer technology company rather than a defense plant, marks a different category of target, and one that speaks to how widely the campaign has widened.
Ukrainian officials have not claimed the strikes or said which facility was the intended target. Kyiv has generally refrained from commenting on specific operations deep inside Russia, and its broader campaign against Russian infrastructure has steadily expanded over the past two years, from oil refineries to power substations and, now, computing infrastructure.
For Yandex, the operational picture is more corrosive than two damaged buildings suggest. Cloud customers make hosting decisions on reliability above almost everything else, and two strikes in 48 hours on the same operator’s facilities will register with every enterprise buyer in the region, and likely with any international partner still hosting workloads on the platform. The company has not said whether it plans to redistribute workloads, add sites, or shift capacity to other facilities, and it has not commented on whether customer contracts or service level commitments are affected.
What comes next
Recovery, not repair, is the hard part. Modern data centers run on specialized networking gear, cooling systems, and server configurations that are not sitting in a warehouse next door, especially under a sanctions regime that limits hardware imports. Yandex’s own language, that it is “very difficult to specify a timeline,” is a signal the damage is more than cosmetic. If modules at Kaluga were “completely disabled,” replacement hardware and re-racked systems will likely take weeks, not days, under normal conditions, and longer than that if specific components are hard to source.
The second question is precedent. If Ukrainian drones are now actively targeting Russian computing infrastructure, every operator in the region faces a planning problem that few enterprise risk models account for: physical attack on the building itself. That has already reshaped how Ukrainian data centers have operated since 2022. Russian operators may now face the same pressures, including dispersal of workloads, physical hardening, and reserve capacity in locations farther from strike range.
For companies that host on Yandex Cloud or depend on Yandex services, the two days of attacks were a reminder that physical infrastructure risk now shares a list with cyber threats, power failures, and sanctions exposure. Yandex has not said whether the attacks will change how it prices, locates, or insures its infrastructure going forward, and the company’s broader customer disclosures have been limited so far to general statements about service availability.