/usr/lib/x86_64-linux-gnu/ is in libtext-bibtex-perl 0.71-1build1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/perl5/
/usr/lib/x86_64-linux-gnu/perl5/5.22/
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/BibTeX.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/BibTeX/
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/BibTeX/Value.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/BibTeX/BibSort.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/BibTeX/File.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/BibTeX/Entry.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/BibTeX/BibFormat.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/BibTeX/Structure.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/BibTeX/Bib.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/BibTeX/Name.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/Text/BibTeX/NameFormat.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/Text/
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/Text/BibTeX/
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/Text/BibTeX/BibTeX.bs
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/Text/BibTeX/BibTeX.so