Ukraine struck and partly disabled a data center operated by Russian technology company Yandex on Friday, a day after it hit a similar but more significant facility, widening the scope of its attacks against Russia after Moscow targeted data hubs inside Ukraine.
Yandex, which is heavily involved in Russia's AI development and is sometimes called "Russia's Google," said its data center in the Kaluga region southwest of Moscow had been struck by Ukrainian drones and partly put out of action.
A day earlier, a Ukrainian attack shut down Yandex's major data hub in Sasovo in the Ryazan region, where two of the three supercomputers used to develop the company's AI model are housed. Yandex has said it is assessing the damage from that strike and cannot confirm whether the equipment can be restored.
Locked in an escalating and deadly war of attrition after more than four years of fighting, both Russia and Ukraine have expanded drone attacks this year on infrastructure targets, from energy facilities and refineries to ports and vessels carrying oil and grain, e-commerce warehouses and, most recently, data centers.
Yandex, whose apps have become an indispensable part of many Russians' lives, said the attacks had struck at the core of its operations and that it was trying to keep its services going.
"Data centers are the iron heart of Yandex. Their operation is critical for services that have become part of people's everyday lives. Millions of users check traffic and plan routes, listen to music, watch movies, order groceries and get answers to their questions," it said in a statement.
"Our technology helps hundreds of thousands of companies run their businesses. They use it to take orders, serve customers and work with partners," it said.
Yandex shares were the biggest faller on the Moscow exchange, down 3.75%.
"The risks involve not only the potential temporary unavailability of Yandex services and lost revenue in specific segments but also the company's extensive base of B2B clients," said Maryana Lazaricheva, head of equity research at T-Investments.
She said the company could redistribute some of the load to its other data centers. "However, if the chain of attacks continues, this possibility vanishes, which could lead to even more severe consequences."
The full scale of the disruption caused by the attacks was not immediately clear, although messages appeared on at least one Yandex app warning of potential problems in its operation.
Yandex said it was working around the clock to try to restore services that had been disrupted.
"Right now this is our most important task, but unfortunately it is not an easy one," it said in the same statement.
Russia has struck Ukrainian data centers and telecommunications infrastructure over the past month, including targets in central Kyiv.
"We always respond in mirror-like fashion," Ukrainian President Volodymyr Zelenskyy said on Thursday. "You all know, they have been hitting and continue to hit our data centers. We are responding. I can't share all the details."
Ukraine has previously targeted the warehouses of specific companies inside Russia which it deems central to Russia's economy, including e-commerce giants Wildberries and Ozon, which then prompted Russia to strike their Ukrainian equivalents.
Yandex operates five data centers, two of which have already been hit. Two of the other three are in the Moscow region, and another is in the Vladimir region, according to publicly available information.
Yandex said in 2021 that the Sasovo data hub, which was struck on Thursday, hosted two of its three supercomputers built around Nvidia A100 chips, which it uses to train its YandexGPT large AI model. Yandex has declined to say whether the supercomputers were affected by the attack.
Multiple online services in Russia reported technical issues on Thursday, including real estate aggregator Cian, a book portal called Litmarket, and the websites of Russian Railways and professional football club Spartak Moscow.
Previous Ukrainian attacks on Russia have led to fuel shortages and queues at petrol stations, losses for tens of thousands of small businesses involved in e-commerce, and higher inflation as rising fuel costs feed through to consumer prices.
Russian attacks on Ukrainian data centers have forced some of them to suspend operations after sustaining damage, while 100,000 households suffered temporary internet outages after one attack.
Ukraine's digital minister told Reuters last month that the country was moving digital infrastructure underground in response to Russian attacks.
