The Revil ransomware group, also known as Sodinokibi, was a notorious cybercriminal organization that operated a Ransomware-as-a-Service model, causing substantial economic damage. Active from 2019 to 2022, Revil targeted high-profile organizations like Kaseya and JBS Foods, employing double extortion tactics. Law enforcement efforts led to arrests and fund seizures, but signs of the group's resurgence have emerged. The group's hierarchical structure, attack patterns, and financial impact underscore the challenges in combating ransomware threats. Decryption tools and proactive cybersecurity measures are critical in mitigating the risks posed by groups like Revil.