This was stated in a comment by the press service of the SBU to Ukrinform.

“Responsibility for the attack has already been claimed by one of the Russian pseudo-hacker groups. This is a hacking unit of the Main Directorate of the General Staff of the Armed Forces of the Russian Federation (better known as GRU). In this way, it publicly legalizes the results of criminal activities, the SBU reported.

Currently, cyber experts of the Security Service of Ukraine and experts of “Kyivstar” continue work on the restoration of the network in cooperation with other state institutions.

According to preliminary calculations of the Ministry, on December 13, it is planned to restore fixed internet for households, as well as launch mobile communications and the Internet.

The SBU stated that the digital infrastructure of “Kyivstar” was seriously damaged, so it requires time to restore all services in accordance with the necessary security protocols.

The agency documents Russia’s cyberattack on Ukraine’s civilian infrastructure as another war crime.

According to media reports, Russian hackers from the so-called Solntsepek group claimed responsibility for the cyber attack on the Ukrainian mobile phone operator Kyivstar.

It was claimed that the hacker group destroyed 10 thousand computers, more than 4 thousand servers, and all cloud data storage and backup systems.

“We attacked Kyivstar because the company provides communications with the Ukrainian Armed Forces, as well as with state institutions and power structures of Ukraine,” the message said.

On the morning of December 12, a technical malfunction occurred in the work of “Kyivstar”, one of the largest mobile operators in Ukraine. The company later confirmed that it was the victim of a “strong hacker attack.”