/usr/lib/freefoam/plugins1/libengine.so is in libfreefoam1 0.1.0+dfsg-1build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/freefoam/plugins1/../libengine.so.1
/usr/lib/freefoam/plugins1/../libengine.so.1