The Kangaroo ransomware is the latest version of the Apocalypse Ransomware. It uses a legal notice as a ransom note that is displayed to all victims before they login to their computer. This makes it so a victim has to view the ransom note before they are able to login to Windows. It essentially locks a user out of Windows until they pay the ransom or remove the infection. In order to gain access to the Windows desktop again, a victim will need to disable the Kangaroo executable from running.
Source: https://www.bleepingcomputer.com/news/security/the-kangaroo-ransomware-not-only-encrypts-your-data-but-tries-to-lock-you-out-of-windows/