/usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/jid1-F9UJ2thwoAm5gQ@jetpack is in xul-ext-lightbeam 1.2.1+dfsg-1ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/mozilla/extensions/{ec8030f7-c20a-464f-9b0e-13a3a9e97384}/../../../xul-ext/lightbeam