  We obtained new hairy black hole solutions in Einstein-scalar theory,
including asymptotic flat, de Sitter and anti-de Sitter black holes. The theory
is inspired by Ref. [1], where traversable wormhole solutions from an
Einstein-phantom scalar theory are constructed. In this work, we found new
black hole solutions in an Einstein-normal scalar theory. Comparing with
Schwarzschild metric, the hairy black holes have two interesting properties: i)
the areas of the black holes are always smaller than the same mass
Schwarzschild black holes; ii) A naked singularity with positive mass arises
when the black hole mass decreases. The energy conditions for the black holes
and naked singularities are checked. We found that, as hairy black holes, the
null energy condition(NEC) and the strong energy condition(SEC) are hold, while
the weak energy condition(WEC) is violated in the vicinity of black hole
horizon. The naked singularity respects to all three energy conditions. We also
investigate the quasinormal modes(QNMs) of the hairy black holes by a test
scalar field. The results indicate that one can distinguish hairy black holes
with the same mass Schwarzschilid black hole by their QNM spectra.
