/usr/lib/python2.7/dist-packages/mox.py is in python-mox 0.5.3-1ubuntu5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/python2.7/dist-packages/../../../share/pyshared/mox.py
/usr/lib/python2.7/dist-packages/../../../share/pyshared/mox.py