https://www.bleepingcomputer.com/news/security/russian-hackers-wiped-thousands-of-systems-in-kyivstar-attack/

The Russian hackers behind a December breach of Kyivstar, Ukraine's largest telecommunications service provider, have wiped all systems on the telecom operator's core network.

Following the incident, Kyivstar's mobile and data services went down, leaving most of its 25 million mobile and home internet subscribers without an internet connection.