/usr/share/ppd/hp-ppd/HP/ is in hp-ppd 0.9ubuntu2+really-0.2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/ppd/hp-ppd/HP/HP_Business_Inkjet_2500C_Series.ppd
/usr/share/ppd/hp-ppd/HP/HP_ColorLaserJet_5-5M.ppd
/usr/share/ppd/hp-ppd/HP/HP_DeskJet_350C.ppd
/usr/share/ppd/hp-ppd/HP/HP_DeskJet_600C_Photo_Series.ppd
/usr/share/ppd/hp-ppd/HP/HP_DeskJet_600C_Series.ppd
/usr/share/ppd/hp-ppd/HP/HP_DeskJet_630C.ppd
/usr/share/ppd/hp-ppd/HP/HP_DeskJet_800C_Series.ppd
/usr/share/ppd/hp-ppd/HP/HP_DeskJet_900C_Series.ppd
/usr/share/ppd/hp-ppd/HP/HP_DeskJet_990C.ppd
/usr/share/ppd/hp-ppd/HP/HP_LaserJet_3200M.ppd
/usr/share/ppd/hp-ppd/HP/HP_LaserJet_5.ppd
/usr/share/ppd/hp-ppd/HP/HP_LaserJet_5000_Series.ppd
/usr/share/ppd/hp-ppd/HP/HP_LaserJet_5P.ppd
/usr/share/ppd/hp-ppd/HP/HP_LaserJet_6P.ppd