/usr/lib/x86_64-linux-gnu/libcrypto++.so is in libcrypto++-dev 5.6.4-8.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libcrypto++.so.6.0.0
/usr/lib/x86_64-linux-gnu/libcrypto++.so.6.0.0