NSA & CISA Issue Warning About Russian GRU Brute-Force Cyberattacks Against US, Global Orgs. Russia’s GRU military intelligence agency is engaging in old-school brute-force hacking to gain credentials from their targets. They use leaked credentials as well as password-guessing methods to steal the credentials in order to move throughout the target to steal information. The GRU attackers are also dropping exploits of two older and patched Microsoft Server vulnerabilities to dig deeper into the targeted networks.”]