/usr/lib/x86_64-linux-gnu/libksba.so.8 is in libksba8 1.3.3-1ubuntu0.16.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libksba.so.8.11.4
/usr/lib/x86_64-linux-gnu/libksba.so.8.11.4