/usr/lib/x86_64-linux-gnu/libndpi.so is in libndpi-dev 1.7.1~git20151130.6f3d5a7-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libndpi.so.3.0.0
/usr/lib/x86_64-linux-gnu/libndpi.so.3.0.0