Got strange texts & "LIBERTY" on terminal, possible virus?

The official definition of "open source" requires allowing forks and derivatives that are closed source.

I have no idea what "official definition" you are referring to, but that is certainly not what the Open Source Initiative defines as open source.

https://opensource.org/osd

Nothing on that page specifies that an open source license must allow closed source derivatives. The GNU GPL is even explicitly listed as a fully OSI-approved open source license.

You are correct that the FSF considers "free software" to be something more than "open source", in that "free software" explicitly forbids any kind of closed-source derivative. But that doesn't imply that "open source" specifically requires that closed-source derivatives be permitted.

/r/MacOS Thread Parent Link - i.redd.it