/usr/lib/x86_64-linux-gnu/libssh_threads.so.4 is in libssh-4 0.8.0~20170825.94fa1e38-1build1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libssh_threads.so.4.5.0
/usr/lib/x86_64-linux-gnu/libssh_threads.so.4.5.0