Malware
VirLock
Polymorphic parasitic file infecting virus which transforms files into copies of itself.
VirLock is a Windows malware family.
Background
A polymorphic, parasitic file infector that converts the files it touches into further copies of itself. On top of that, it employs screen-locking as a ransomware tactic.
Source: Malpedia (Fraunhofer FKIE).