/usr/lib/pyshared/python2.7/gtk-2.0/gnash.so is in python-gtk-gnash 0.8.11~git20130903-3ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/pyshared/python2.7/gtk-2.0/../../../python2.7/dist-packages/gtk-2.0/gnash.so