/usr/lib/x86_64-linux-gnu/libpth.so is in libpth-dev 2.0.7-20.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libpth.so.20.0.27
/usr/lib/x86_64-linux-gnu/libpth.so.20.0.27