From 2-spyware.com
Kolz ransomware is another dangerous virus that manages to encrypt[1] most of the useful files and then demands a ransom to be paid for the return. The virus enters the computer system and disrupts important data in various formats: images, documents, videos, archives, and other files. Users see a ransom note file, named as _readme.txt, in each computer folder with locked files and on the desktop. This way, hackers let victims find out what happened to their files and what they have to do to decrypt them. However, the ransomware creators claim that the only option for the victim is to pay a ransom. This shouldn’t be considered a solution because criminals focus on getting money, not helping victims.