Malware
ACBackdoor
A Linux backdoor that was apparently ported to Windows.
ACBackdoor is a Windows malware family.
Background
Originally a Linux backdoor that seems to have been ported over to Windows; this entry covers the Windows variant. The Linux edition appears to have come first, with the Windows port arriving later and lacking some features. While the Linux build adds persistence and certain process-manipulation capabilities, both variants reportedly provide command-line access, program execution, and self-update functionality.
Source: Malpedia (Fraunhofer FKIE).