We report the discovery of an unusual low-ionization broad absorption line quasar at z=1.776 which exhibits absorption lines from many excited states of Fe II. This member of the rare class of ``FeLoBAL'' quasars was serendipitously found in a mid-infrared (MIR) survey of distant clusters carried out with the ISOCAM camera. ISO J005645.1-273816 has a high MIR to UV luminosity ratio, suggesting a strong dust obscuration plus emission from very hot dust. This characteristic makes MIR surveys particularly efficient at detecting LoBAL quasars. Based on observations with ISO, an ESA project with instruments funded by ESA Member States with the participation of ISAS and NASA and observations collected at the European Southern Observatory, Paranal, Chile (ESO No 65.O-0563 A), at La Silla, Chile (ESO No 67.A-0253 A).