  In this paper we present a simple extension of the minimal supersymmetric
standard model [MSSM] which "naturally" produces the INTEGRAL photon signal.
The model can be embedded in an SU(5) grand unified theory [GUT] with gauge
mediated SUSY breaking. The new ingredients are the addition of several MSSM
singlets/moduli. While the masses of the singlets are at the weak scale, their
mass splittings are suppressed by chiral symmetry breaking and naturally lie
around an MeV. The decay of the heavier modulino to the lighter one with the
associated production of electron - positron pairs explains the INTEGRAL
signal. Finally, the detection of diffuse gamma rays from internal
bremsstrahlung in the galactic halo would be a suggestive indication of dark
matter decays associated with the 511 keV line, and is an unambiguous
additional prediction of this model.
