Is it correct is say:
This file is part of X and is distributed...
or this:
This file is part of X and distributed...
What's the rule here?
Is it correct is say:
This file is part of X and is distributed...
or this:
This file is part of X and distributed...
What's the rule here?
When making lists of things, good English style recommends that you write all the elements in exactly the same way.
The soup is thin, weak, and watery.
The soup is cooked in a tureen, stirred with a spoon, and served in a bowl.
So the question is, are you listing features of the file? Or mentioning separate but related facts? Both are fine, but if you want to imply multiple features, you would use the pattern:
the [thing] is [A] and [B]
Otherwise you could repeat "is" to denote the actions are unrelated:
the [thing] is [A], and then it is [B].
Note again this is simply style, not grammar. Both of your examples are fine as written.