/usr/lib/x86_64-linux-gnu/libelf.so is in libelf-dev 0.158-0ubuntu5.3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libelf.so.1
/usr/lib/x86_64-linux-gnu/libelf.so.1