Malware
HiddenTear
aka Cryptear · FuckUnicorn
HiddenTear is an open source ransomware developed by a Turkish programmer and later released as proof of concept on GitHub.
HiddenTear, also known as Cryptear, FuckUnicorn, is a Windows malware family.
Background
HiddenTear is open source ransomware written by a Turkish developer who subsequently published it on GitHub as a proof of concept. It creates a local symmetric key to encrypt a folder that can be configured (the default target was /test) and transmits that key to a central C&C server. Its compact payload made it practical as a genuine attack tool in email phishing campaigns, and derivative versions continue to appear in attacks today.
Source: Malpedia (Fraunhofer FKIE).