ESET experts uncovered a previously undocumented piece of malware that had been observed targeting high-performance computing clusters (HPC) Kobalos is a small Linux malware, only 25 Kb for x86-64 samples, that also works on FreeBSD and Solaris, and possibly on Windows and AIX systems as well. The name comes from a small sprite from Greek mythology, a mischievous creature fond of tricking and frightening mortals. The malware is a generic backdoor in the sense that it contains broad commands that dont reveal the intent of the attackers.”]
Source: https://securityaffairs.co/wordpress/114137/malware/kobalos-linux-malware.html