/usr/share/perl5/Mail/SpamAssassin/Plugin/ is in spamassassin 3.3.2-2ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/perl5/Mail/SpamAssassin/Plugin/ASN.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/AWL.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/AccessDB.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/AntiVirus.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/AutoLearnThreshold.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/Bayes.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/BodyEval.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/BodyRuleBaseExtractor.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/Check.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/DCC.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/DKIM.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/DNSEval.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/FreeMail.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/HTMLEval.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/HTTPSMismatch.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/Hashcash.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/HeaderEval.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/ImageInfo.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/MIMEEval.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/MIMEHeader.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/OneLineBodyRuleType.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/PhishTag.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/Pyzor.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/Razor2.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/RelayCountry.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/RelayEval.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/ReplaceTags.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/Reuse.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/Rule2XSBody.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/SPF.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/Shortcircuit.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/SpamCop.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/Test.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/TextCat.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/URIDNSBL.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/URIDetail.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/URIEval.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/VBounce.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/WLBLEval.pm
/usr/share/perl5/Mail/SpamAssassin/Plugin/WhiteListSubject.pm