/usr/share/mozilla/extensions/{92650c4d-4b8e-4d2a-b7eb-24ecf4f6b63a}/{DDC359D1-844A-42a7-9AA1-88A850A938A8} is in xul-ext-downthemall 2.0.17-1.
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/downthemall