  We show that the existence of new, light gauge interactions coupled to
Standard Model (SM) neutrinos give rise to an abundance of sterile neutrinos
through the sterile neutrinos' mixing with the SM. Specifically, in the mass
range of MeV-GeV and coupling of $g' \sim 10^{-6} - 10^{-2}$, the decay of this
new vector boson in the early universe produces a sufficient quantity of
sterile neutrinos to account for the observed dark matter abundance.
Interestingly, this can be achieved within a natural extension of the SM gauge
group, such as a gauged $L_\mu-L_\tau$ number, without any tree-level coupling
between the new vector boson and the sterile neutrino states. Such new leptonic
interactions might also be at the origin of the well-known discrepancy
associated with the anomalous magnetic moment of the muon.
