/usr/lib/x86_64-linux-gnu/libQApt.so is in libqapt-dev 3.0.4-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libQApt.so.3
/usr/lib/x86_64-linux-gnu/libQApt.so.3