/usr/lib/x86_64-linux-gnu/libkrb5support.so is in libkrb5-dev 1.12+dfsg-2ubuntu4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/mit-krb5/libkrb5support.so
/usr/lib/x86_64-linux-gnu/mit-krb5/libkrb5support.so