Malware
DarkSide
aka BlackMatter
FireEye describes DARKSIDE as a ransomware written in C and configurable to target files whether on fixed, removable disks, or network shares.
DarkSide, also known as BlackMatter, is a Windows malware family.
Background
According to FireEye, DARKSIDE is a C-language ransomware that can be configured to encrypt files on fixed drives, removable media, or network shares. Affiliates are able to tailor the malware and produce builds aimed at particular victims.
Source: Malpedia (Fraunhofer FKIE).