  We study the formation of bright solitons in the impurity component of
Bose-Einstein condensate (BEC)-impurity mixture by using the time-dependent
Hartree-Fock-Bogoliubov theory. While we assume the boson-boson and
impurity-boson interactions to be effectively repulsive, their character can be
changed spontaneously from repulsive to attractive in the presence of strong
anomalous correlations. In such a regime the impurity component becomes a
system of effectively attractive atoms leading automatically to the generation
of bright solitons. We find that this soliton decays at higher temperatures due
to the dissipation induced by the impurity-host and host-host interactions. We
show that after a sudden increase of the impurity-boson strength a train of
bright solitons is produced and this can be interpreted in terms of the
modulational instability (MI) of the time-dependent impurity wave function.
