  While the low-energy excess observed at MiniBooNE remains unchallenged, it
has become increasingly difficult to reconcile it with the results from other
sterile neutrino searches and cosmology. Recently, it has been shown that
non-minimal models with new particles in a hidden sector could provide a better
fit to the data. As their main ingredients they require a GeV-scale $Z'$,
kinetically mixed with the photon, and an unstable heavy neutrino with a mass
in the 150 MeV range that mixes with the light neutrinos. In this letter we
point out that atmospheric neutrino experiments (and, in particular,
IceCube/DeepCore) could probe a significant fraction of the parameter space of
such models by looking for an excess of "double-bang" events at low energies,
as proposed in our previous work (arXiv:1707.08573). Such a search would probe
exactly the same production and decay mechanisms required to explain the
anomaly.
