Belarusian hacktivists spent two years inside Russian healthcare network, researchers say

Researchers at Russian firm Solar attribute a long-running intrusion (earliest signs in early 2024, discovered Dec 2025) into a Russian healthcare organization's network to the Belarusian Cyber Partisans; the attackers used the Vasilek Windows backdoor to exfiltrate sensitive medical data and maintained access for espionage and trusted-relationship attacks without overtly destructive activity, potentially enabling lateral pivoting to other healthcare organizations connected to the compromised infrastructure.