Recent results for dark matter (DM) and hidden sectors using the LHC Run 2 data collected by the CMS experiment are presented. Four searches are discussed: DM produced with a pair of $W$ boson, prompt GeV scale di-muon resonance, inelastic DM with displaced muons and resonant production of strongly coupled DM. These searches analyzed proton-proton collision data at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 137 fb$^{-1}$ or 96.6 fb$^{-1}$ when using special "scouting" triggers. The dedicated trigger and novel identification and reconstruction algorithms employed in the analyses are discussed. No significant deviation from the Standard Model is observed and exclusion limits for the benchmark new physics models considered are set.