/usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/{F8147CF4-B9E3-445B-AA87-081ED66548F8} is in xul-ext-dispmua 1.6.8-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/../../../xul-ext/dispmua