Peculiar anisotropic stationary spherically symmetric solution of
  Einstein equations
  Motivated by studies on gravitational lenses, we present an exact solution of
the field equations of general relativity, which is static and spherically
symmetric, has no mass but has a non-vanishing spacelike components of the
stress-energy-momentum tensor. In spite of its strange nature, this solution
provides with non-trivial descriptions of gravitational effects. We show that
the main aspects found in the \emph{dark matter phenomena} can be
satisfactorily described by this geometry. We comment on the relevance it could
have to consider non-vanishing spacelike components of the
stress-energy-momentum tensor ascribed to dark matter.
