  Neutrino masses and light (keV-GeV) sterile neutrinos can arise naturally via
a modified, low energy seesaw mechanism if the right-handed neutrinos are
charged under a new symmetry broken by a PeV scale vacuum expectation value,
presumably tied to supersymmetry breaking. The additional field content also
allows for freeze-in production of sterile neutrino dark matter. This framework
can accommodate the recently observed 3.5 keV X-ray line, while a
straightforward extension of the framework, using the new symmetry and the PeV
energy scale, can explain the PeV energy neutrino events at IceCube. Together,
these can therefore be taken as hints of the existence of a PeV scale
supersymmetric neutrino sector.
