  We present a single-field string inflationary model which allows for the
generation of primordial black holes in the low mass region where they can
account for a significant fraction of the dark matter abundance. The potential
is typical of type IIB fibre inflation models and features a plateau at CMB
scales and a near inflection point at large distance scales where the power
spectrum is enhanced due to a period of ultra slow-roll. The tunability of the
underlying parameters is guaranteed by scanning through the string landscape
and their stability against quantum corrections is ensured by an effective
shift symmetry.
