Malware
BlueShell
According to AhnLab, BlueShell is a backdoor malware developed in Go language, published on Github, and it supports Windows, Linux, and Mac operating systems.
BlueShell is a Windows malware family.
Background
Per AhnLab, BlueShell is a Go-based backdoor that was released on Github and runs across the Windows, Linux, and Mac operating systems. While the original Github repository appears to have since been removed, the BlueShell source code remains available through other repositories. The presence of an explanatory ReadMe file written in Chinese suggests that its author may be a Chinese user.
Source: Malpedia (Fraunhofer FKIE).