/usr/share/mozilla/extensions/{aa3c5121-dab2-40e2-81ca-7ea25febc110}/vwof@drev.com is in xul-ext-video-without-flash 3.1.1-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/mozilla/extensions/{aa3c5121-dab2-40e2-81ca-7ea25febc110}/../../../xul-ext/video-without-flash