/usr/lib/libkontactinterface.so.4 is in libkontactinterface4a 4:4.14.2-2+deb8u2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libkontactinterface.so.4.14.2
/usr/lib/libkontactinterface.so.4.14.2