Files with ruby extension may be also encountered as files that have been encrypted and renamed by the Ruby ransomware.
RUBY file extension - Ruby ransomware affected file
What is ruby file? How to open ruby files?
File type specification:
File extension ruby is related to Ruby ransomware that appeared in early May 2017. Works pretty much like other ransomware, it leaves a note saved as rubyLeza.html file.
Note: Not related to Ruby programming language.