https://www.bleepingcomputer.com/news/security/russian-sandworm-hackers-pose-as-ukrainian-telcos-to-drop-malware/

The Russian state-sponsored hacking group known as Sandworm has been observed masquerading as telecommunication providers to target Ukrainian entities with malware.

Sandworm is a state-backed threat actor attributed by the US government as part of the Russian GRU foreign military intelligence service.