The sudoers file is a hidden Unix file that determines, among other things, who is allowed to get root permissions in a Unix shell, and how. The modification made to the sudoers file, in this case, allowed the app to gain root permissions via a Unix shell without needing a password.
Read more here – https://blog.malwarebytes.org/mac/2015/08/dyld_print_to_file-exploit-found-in-the-wild/