Start by spelling those chords as:
Fm, B♭m, E♭, C
Now look at all the note from these chords:
F, A♭, C; B♭, D♭, F; E♭, G, B♭; C, E, G
In order, these are the set:
F, G, A♭, B♭, C, D♭, E♭, E♮, F
This is just the notes of the F natural minor scale (or F harmonic minor scale), but with both E♭ and E♮.
Music in a minor key will often takes notes from the natural, harmonic, and melodic minor scales.
It is important to understand the difference between a key and a scale—see some of the answers in the post: Difference between keys and scales?
With F as the tonic, in roman numerals theses chords are:
i, iv, VI, V
which is nothing remarkable.