Technically, there is no guitar in this, but if there was, a C#m7b5 chord would appear in the chorus of the song. If you decide to cover this on guitar, you’ll need to learn this diminished chord.
All the chords built on other notes in the scale of C are minor, except chord VII - the notes B – D – F, which is diminished. When a seventh is added to a chord this is known as a seventh chord.