Four days in October: drones hit three of Yandex's biggest data centres

Just after 1.30am on 8 October 2026, a fire broke out on the roof of an unremarkable industrial building in Sasovo, a small town in Russia’s Ryazan region, south-east of Moscow. By sunrise, people across Russia found that apps they used every day had stopped working, and the company behind them had confirmed that a drone had hit one of its most important data centres. Source [1]

That company was Yandex, often described as Russia’s Google. Over the next four days, drones reached three of its biggest data centres – in Sasovo, Kaluga and Vladimir. In that time Russia learned a lesson it had never had to learn before: a country’s digital life sits in a small number of buildings, and those buildings can burn.

What Yandex is

Yandex is Russia’s largest technology company. It runs the country’s most popular search engine, but that is only the front door. Behind it sits a whole ecosystem: maps and navigation, a taxi service, food delivery, email, cloud storage, a payments platform, a voice assistant called Alice, and a family of artificial intelligence models sold as YandexGPT.

There is a quieter layer too. Through Yandex Cloud, the company rents computing power to thousands of businesses – banks, retailers, media outlets, transport operators and government websites – that have never put the Yandex logo on anything. When those servers stop, the damage spreads well beyond one company’s apps.

It started in Kyiv

On 23 September 2026, Russian drones attacked targets in and around the Ukrainian capital for hours. Ukraine’s Ministry of Digital Transformation said the attacks disrupted internet service for about 100,000 households in Kyiv and the surrounding region. Source [7] Russia’s Defence Ministry openly said it had targeted data centres, claiming they processed and transmitted intelligence for Ukraine’s armed forces. !CLAIMEDClaimed: stated by a government, army or official, but not independently verified. – Claimed: stated by a government, army or official, but not independently verified. Ukraine’s foreign minister, Andrii Sybiha, rejected that, calling the facilities critical civilian infrastructure.

It was not a one-off. Over the following days, Russian strikes damaged or destroyed data centres belonging to at least eight companies in Ukraine, some more than once, including sites in central Kyiv.

So when the first Yandex building caught fire, President Volodymyr Zelenskyy did not pretend to be surprised. On 8 October he told journalists that Russia had been hitting Ukrainian data centres and was still doing it, and that Ukraine always responds “in a mirror-like fashion”. He added that he could not go into details. That phrase is the key to what followed: not a new front opened out of nowhere, but a reply aimed at the same kind of target.

Day one: Sasovo

The Ryazan regional authorities were careful. The governor reported that two Ukrainian drones had been shot down overnight and that a fire had broken out on the roof of an enterprise in the Sasovo district, without naming it. !CLAIMEDClaimed: stated by a government, army or official, but not independently verified. – Claimed: stated by a government, army or official, but not independently verified.

Yandex was more direct. A spokesperson told AFP that a drone attack had caused a fire at its Sasovo data centre and that the facility had stopped working entirely. Nobody was hurt; disruptions began at 1.31am. A few hours later, Yandex said it could not yet confirm whether the equipment in Sasovo could be restored at all. Source [1] ✓CONFIRMEDConfirmed: backed by at least two independent, reliable sources or by direct evidence. – Confirmed: backed by at least two independent, reliable sources or by direct evidence.

Since 2014, Yandex had used part of the grounds of the former Sasta machine-tool plant. According to the independent Russian outlet Astra, Sasta also serves as a production base for defence enterprises and appears on the sanctions lists of several Western countries. Source [3] Whether the drones were aimed at the server hall, the factory or both was never made clear.

Inside the Sasovo facility were two of Yandex’s three supercomputers, the machines it uses to train its neural networks and large language models, named after the scientists Chervonenkis and Lyapunov. Chervonenkis was the crown jewel: when it went into service in 2021, it ranked 19th on the TOP500 list of the world’s most powerful supercomputers, the strongest publicly known machine in Russia.

As far as anyone could tell, it was the first strike of its kind. In more than four and a half years of full-scale war, Ukrainian drones had hit refineries, airfields, ammunition depots and factories deep inside Russia, but no one had confirmed a strike on Russian data infrastructure before that night.

Markets reacted within hours: Yandex shares fell by more than 3% on the Moscow Exchange. The outage also spread to customers built on Yandex infrastructure – the websites of Russian Railways and the mobile operator MegaFon went down, along with several Russian media sites.

Day two: Kaluga

Large tech companies plan for losing a site. They shift work elsewhere and fix the damage – as long as the other sites stay standing. They did not.

On 9 October, drones reached the Kaluga region, south-west of Moscow. The target was a Yandex data centre in the Grabtsevo industrial park, which the company describes as its largest, with a design capacity of about 63 megawatts. Yandex confirmed that part of its infrastructure in Kaluga was out of action and that several modules had been completely knocked out, adding that it was very difficult to give any timeline for recovery. Source [2] ✓CONFIRMEDConfirmed: backed by at least two independent, reliable sources or by direct evidence. – Confirmed: backed by at least two independent, reliable sources or by direct evidence. The company said the attacks had hit “the core” of its operations.

The governor of Kaluga region, Vladislav Shapsha, said drones had struck the regional capital and several districts and that nine people had been injured.

This time, someone took credit. Fire Point, a Ukrainian defence manufacturer, announced on Telegram that its FP-1 drones – long-range, one-way attack drones designed to fly deep into Russian territory – had struck the Yandex data centre in Kaluga. Source [4] !CLAIMEDClaimed: stated by a government, army or official, but not independently verified. – Claimed: stated by a government, army or official, but not independently verified. Kyiv’s government, as often, did not comment officially. Yandex shares fell again, by about 4%.

Day four: Vladimir

In the early hours of Sunday 11 October, drones hit a Yandex data centre in Vladimir, a historic city east of Moscow. Later that day the company announced that operations there had been completely suspended. No injuries were reported. Source [2] ✓CONFIRMEDConfirmed: backed by at least two independent, reliable sources or by direct evidence. – Confirmed: backed by at least two independent, reliable sources or by direct evidence.

Vladimir mattered for a particular reason: it housed Yandex’s third supercomputer, Galushkin. Count them up – Chervonenkis and Lyapunov in Sasovo, Galushkin in Vladimir. In four days, every supercomputer Yandex had built to train its artificial intelligence sat inside a building hit by a drone.

Yandex operates five large data centres. Three had now been struck in four days: two shut down completely, and the largest partly crippled. What remained, mainly the facilities at Mytishchi and Ivanteyevka in the Moscow region, had to carry a load they were never designed to carry alone. That is why the sequence mattered as much as any single strike. Each strike took away part of the safety net the previous one had pushed the company onto.

What users saw

For many Russians, the weekend of 10 and 11 October was the first time they had seen a digital backbone fail all at once. Yandex Cloud showed more than 80 of its services down, including compute, object storage and the YandexGPT interface. Banking apps, ride-hailing services and retailers reported failures.

The company took emergency steps. It said rival cloud providers had agreed to let its customers quickly move their data and applications elsewhere – sending business to competitors to keep those customers alive. It also rewrote its user agreement so that drone and missile attacks now count as force majeure, the legal term usually reserved for earthquakes and floods. It was an open admission that the company expected the danger to continue.

The most alarming moment came from money. Yandex Pay went dark: users could not check balances, pay for purchases or transfer money. The head of Yandex’s fintech business went public to say that the money was safe – it was not physically stored in the data centres, account records were kept in several copies at different sites, and checks had found no records lost. He gave no firm timeline for full recovery.

The effects crossed borders. Yandex’s taxi and delivery apps are widely used in Central Asia, and users in Kazakhstan, Kyrgyzstan and Uzbekistan suddenly could not order rides, food or groceries. A strike on a building in central Russia left people in Kazakh and Kyrgyz cities standing on street corners, unable to get a taxi.

Moscow’s response

On 12 October, Maksut Shadayev, Russia’s minister of digital development, told a joint meeting of State Duma committees that Yandex had faced “an unprecedented attack”, and that his ministry was now working with the Defence Ministry on measures to protect Russia’s data centres. That sentence says a lot. Data centres were built as commercial property, designed for cheap power, efficient cooling and fast connections – not to survive explosives falling from the sky.

On 15 October, Vladimir Putin spoke at the congress of the business association Delovaya Rossiya, answering Tatyana Kim, founder of the online retailer Wildberries, who had raised Ukrainian strikes on the warehouses of Wildberries and its rival Ozon. Putin made an unusual admission: Ukraine keeps taking steps that, frankly, Russia probably should have anticipated, but officials had believed such ideas would not occur to them. He played down the latest strikes on refineries as insignificant and insisted that Ukraine had started this cycle and Russia was only responding. !CLAIMEDClaimed: stated by a government, army or official, but not independently verified. – Claimed: stated by a government, army or official, but not independently verified. It is not clear whether he was referring to Yandex, the warehouses or the wider campaign, but the admission itself was striking.

The machines that may not come back

Rebuilding will not be quick. The Russian business daily Kommersant reported that repairing or replacing the equipment at the three damaged sites could take up to six months – and that covers the general server infrastructure. Source [5]

The supercomputers are a much harder problem. All three are built around high-end processors and Nvidia A100 accelerators, the chips that power modern AI training. Since 2022, Western sanctions have restricted the shipment of exactly that hardware to Russia.

Experts interviewed by the Russian science outlet T-invariant, whose analysis was republished by Meduza, said all three machines had probably suffered serious damage from fire and smoke. Source [6] Part of the problem is how Yandex cools its buildings: its data centres draw in outside air through filters, which is efficient in a cold climate but means soot from a fire can be pulled across circuit boards, corroding contacts and even creating tiny conductive bridges. Cleaning such equipment, if it can be saved at all, could take months; replacing the specialised components could take one to two years, if suitable chips can be found at all through grey markets at inflated prices.

Yandex has said very little about the supercomputers since the attacks and has not confirmed whether Chervonenkis, Lyapunov or Galushkin survived. ?UNVERIFIEDUnverified: reported, but we could not check it. Treat with caution. – Unverified: reported, but we could not check it. Treat with caution. A burned roof can be rebuilt in a season, and a server hall re-equipped with ordinary hardware in months. But machines assembled before the toughest sanctions took hold may not come back in anything like their old form.

A claim that spread faster than the facts

Within days, posts appeared suggesting that Russian propaganda bots on social media had gone quiet after the attacks, and Zelenskyy remarked that there seemed to be less hatred and fewer provocations online. There are no independently verified figures showing that. ?UNVERIFIEDUnverified: reported, but we could not check it. Treat with caution. – Unverified: reported, but we could not check it. Treat with caution. Analysts pointed out that a search engine’s automated traffic naturally drops when its servers go offline, and that professional influence campaigns usually run on infrastructure spread across many countries.

The strategic shift

For most of the war, the long-range drone campaign in both directions focused on energy, fuel and military production. In 2026 it broadened. Russia went after Ukrainian data centres, logistics hubs and warehouses; Ukraine hit back at Russian refineries, at the giant warehouses of Wildberries and Ozon, and now at Russia’s most important technology company.

Every widening of the target list creates a new problem for the defender. Russia already struggles to protect refineries spread across a vast territory; now it must think about dozens of large data centres, including the Yandex sites still running near Moscow. Every air-defence system placed beside a server farm is one not protecting something else. For Ukraine the logic is cold: a long-range drone is cheap compared with the value of what it can destroy.

There is a lesson here beyond Russia and Ukraine. Modern economies are built on the idea that “the cloud” is everywhere and nowhere. It is not. It lives in a few warehouses full of machines, fed by power lines and cooled by fans.

What to watch next

Yandex will rebuild: many services came back within days, and the company has the money and engineers to recover much of what it lost. The open questions are whether Moscow can shield its remaining data centres without pulling defences away from the front, whether Russia will escalate its own attacks on Ukraine’s digital infrastructure in response, and whether the war has simply found a new kind of target that both sides will keep hitting.