/usr/lib/x86_64-linux-gnu/liblapack_atlas.so is in libatlas-base-dev 3.10.3-5.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/liblapack_atlas.so.3.10.3
/usr/lib/x86_64-linux-gnu/liblapack_atlas.so.3.10.3