Neutrinos can escape dense environments, otherwise opaque to photons, and travel cosmic distances unscathed by background radiation or magnetic fields. They are ideal cosmic messengers and these features make them naturally attractive probes of fundamental particle physics properties, possibly tiny in size, at energy scales unreachable by any other means. Moreover, their reach into the regime of fundamental physics searches, not previously available, provides a complementary study to cosmological and laboratory tests. In this talk, I will review the status of high-energy neutrino observations and present our results for searches of new physics with a focus on the neutrino portals to dark matter.