/usr/share/texlive/texmf-dist/scripts/pdfjam/ is in texlive-extra-utils 2017.20180305-2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdf180
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdf270
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdf90
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdfbook
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdfflip
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdfjam
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdfjam-pocketmod
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdfjam-slides3up
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdfjam-slides6up
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdfjoin
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdfnup
/usr/share/texlive/texmf-dist/scripts/pdfjam/pdfpun