/usr/share/pyshared/zope/pluggableauth/plugins/ is in python-zope.pluggableauth 1.3-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/pyshared/zope/pluggableauth/plugins/__init__.py
/usr/share/pyshared/zope/pluggableauth/plugins/ftpplugins.py
/usr/share/pyshared/zope/pluggableauth/plugins/ftpplugins.zcml
/usr/share/pyshared/zope/pluggableauth/plugins/generic.py
/usr/share/pyshared/zope/pluggableauth/plugins/generic.zcml
/usr/share/pyshared/zope/pluggableauth/plugins/groupfolder.py
/usr/share/pyshared/zope/pluggableauth/plugins/groupfolder.txt
/usr/share/pyshared/zope/pluggableauth/plugins/groupfolder.zcml
/usr/share/pyshared/zope/pluggableauth/plugins/httpplugins.py
/usr/share/pyshared/zope/pluggableauth/plugins/httpplugins.zcml
/usr/share/pyshared/zope/pluggableauth/plugins/idpicker.py
/usr/share/pyshared/zope/pluggableauth/plugins/principalfolder.py
/usr/share/pyshared/zope/pluggableauth/plugins/principalfolder.txt
/usr/share/pyshared/zope/pluggableauth/plugins/principalfolder.zcml
/usr/share/pyshared/zope/pluggableauth/plugins/session.py
/usr/share/pyshared/zope/pluggableauth/plugins/session.zcml