The base is original from the producer (chords and melodies), but is complemented with elements that complement the song that come from samplepacks, usually, vocal chops, guitars, wobbles sections, glitch effects. It is the standard in which most of producers work, in a project you will find MIDI files made by the producer, but also melodic loops.
The Guitar is a 100% royalty free sample from BUYLOOPS.com
The Drums I made from scratch.
Sample pack BUYLOOPS.com - Free Loops Vol. 103
Loop name Lucci 132 Emin (Prod. LuciG)