The SBU reports that mobile operator Kyivstar was attacked by Russian intelligence.

A special unit of Russia’s GRU, masquerading as a pseudo-hacker group, claimed responsibility for the December 12 attack on Kyivstar, the Security Service of Ukraine (SBU) reported.

“Kyivstar’s digital infrastructure has suffered critical damage, so restoring all services in compliance with the necessary security protocols will take time,” the SBU added.

Meanwhile, due to the hacker attack, the shares of Kyivstar’s parent company, VEON, fell by almost 3% during the day to €0.70 per share.

At the same time, American companies Microsoft, Cisco, and Swedish Ericsson are helping Kyivstar resume operations after the large-scale cyberattack, said company director Oleksandr Komarov.

According to him, this attack was the most destructive hack in history. Its purpose was to cripple the country’s critical infrastructure.