Ransomware
ShellLocker
PCRIsk states that ShellLocker is a ransomware-type virus developed using .NET framework.
ShellLocker is a Windows ransomware.
Background
According to PCRIsk, ShellLocker is a ransomware-type virus built on the .NET framework. Jakub Kroustek first identified it, and it is nearly indistinguishable from another ransomware called Exotic.
Once it gets in, the virus encrypts stored data such as video and audio and renames the encrypted files following the "[random_characters].L0cked" pattern (for instance, "sample.jpg" could become "gd&=AA0fgoi.L0cked"). After encryption completes, ShellLocker displays a pop-up window with its ransom demand.
Source: Malpedia (Fraunhofer FKIE).