Russian attack on Ukraine busses part of 'a steady increase in attacks on civilians'

On October 8, Ukrainian forces launched a drone attack on a Yandex data center in Sasovo, Russia, causing a fire and shutting down the facility. This incident disrupted several Yandex services, including Yandex Disk, Yandex Documents, Mail, and its owned services like Cian, Avito, IVI, MegaFon, Russian Railways, T-Bank, and several property developers and media outlets. The attack also impacted other major companies, highlighting the vulnerability of Russia's internet infrastructure to drone strikes.

The data center, part of the former Sasta machine tool factory, houses two of Yandex's three supercomputers used for training neural networks. It's unclear whether these systems were damaged, but the extent of the damage remains uncertain. Yandex's shares fell by over 3% following the attack.

Yandex's data is replicated across four "availability zones," ensuring recovery if data is lost in one location. However, other companies' virtual machines hosted at the Ryazan data center are solely responsible for their own data backups. In the event of an attack, customers could have used Yandex Cloud Backup, which stores data at multiple data centers, or chosen alternative solutions.

Experts suggest that while a single strike on a regional data center may cause local disruptions, it's unlikely to bring down the entire Russian internet. Russia's main data centers are concentrated in Moscow and are well-protected. However, targeted attacks on regional facilities belonging to major providers like Rostelecom, Sber, VK, or Selectel could cause localized disruptions, affecting services for a few hours to a day as administrators reconfigure the systems.