/usr/share/perl5/Perlbal/Plugin/ is in libperlbal-perl 1.80-3.
This file is owned by root:root, with mode 0o755.
..
/usr/share/perl5/Perlbal/Plugin/AccessControl.pm
/usr/share/perl5/Perlbal/Plugin/AutoRemoveLeadingDir.pm
/usr/share/perl5/Perlbal/Plugin/Cgilike.pm
/usr/share/perl5/Perlbal/Plugin/EchoService.pm
/usr/share/perl5/Perlbal/Plugin/FlvStreaming.pm
/usr/share/perl5/Perlbal/Plugin/Highpri.pm
/usr/share/perl5/Perlbal/Plugin/Include.pm
/usr/share/perl5/Perlbal/Plugin/LazyCDN.pm
/usr/share/perl5/Perlbal/Plugin/MaxContentLength.pm
/usr/share/perl5/Perlbal/Plugin/NotModified.pm
/usr/share/perl5/Perlbal/Plugin/Palimg.pm
/usr/share/perl5/Perlbal/Plugin/Queues.pm
/usr/share/perl5/Perlbal/Plugin/Redirect.pm
/usr/share/perl5/Perlbal/Plugin/Stats.pm
/usr/share/perl5/Perlbal/Plugin/Throttle.pm
/usr/share/perl5/Perlbal/Plugin/Vhosts.pm
/usr/share/perl5/Perlbal/Plugin/Vpaths.pm
/usr/share/perl5/Perlbal/Plugin/XFFExtras.pm