Ukraine warns Russian hackers are revisiting past breaches to prepare new attacks

CERT‑UA reports that Russian-linked threat actors (including APT28 and Void Blizzard) have shifted from rapid 'steal-and-go' intrusions to operations focused on long-term access and persistence, reusing prior breaches as footholds and employing advanced social engineering (phone/video calls using local numbers and messaging apps) to increase successful delivery of malicious files; the security and defense sector remains the primary target.