extortion

Cloak ransomware, emerging in 2022, has quickly become a significant threat in the cyber landscape, with a new variant raising concerns due to its advanced capabilities. The group uses initial access brokers and social engineering techniques, including phishing and malicious advertising, to gain network access. The ransomware employs a drive-by download method, disguising itself as legitimate system updates. Cloak may have connections to the Good Day ransomware group and utilizes a variant derived from leaked Babuk ransomware source code. Once delivered, it employs sophisticated mechanisms for extraction and privilege escalation, terminating security processes and modifying system settings to hinder recovery. The encryption process uses Curve25519 and SHA512 algorithms, and it exhibits advanced evasion techniques. Cloak ensures payload persistence by altering Windows registry entries and restricting user actions, disrupting essential system utilities and leading to operational downtime. Its extortion tactics include disguising ransom notes as desktop wallpapers and employing intermittent encryption to maximize damage. The ransomware deletes shadow copies and backups, complicating recovery efforts. Cloak also utilizes a data leak site to publish or sell stolen data if ransom demands are not met, claiming a ransom payment success rate of 91% to 96%. Windows users are advised to implement comprehensive security measures to reduce the risk of attacks.