/usr/lib/x86_64-linux-gnu/libssl.so is in libssl-dev 1.0.1-4ubuntu3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /lib/x86_64-linux-gnu/libssl.so.1.0.0
/lib/x86_64-linux-gnu/libssl.so.1.0.0