From 2-spyware.com
Iiss ransomware is a type of cryptovirus that is classified as a money-extortion-based threat controlled by malicious actors.[1] These threats are known for accessing user machines without permission and encrypting all files on them. This way, cybercriminals behind the malware can ask for a ransom payment in return for a unique key. This is one of the newest versions in Djvu ransomware family that stems from STOP ransomware, known for a long time already. However, this version is not the last probably, because criminals release a new variant once a week, at least.