/usr/lib/libQxtZeroconf.so.0.6 is in libqxt-zeroconf0 0.6.1-4ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libQxtZeroconf.so.0.6.1
/usr/lib/libQxtZeroconf.so.0.6.1