If you have `osquery` deployed to your fleet you can detect compromise with this query:
SELECT * FROM plist WHERE path = "/private/var/db/dslocal/nodes/Default/users/root.plist" AND key = "passwd" AND length(value) > 1;
SELECT * FROM plist WHERE path = "/private/var/db/dslocal/nodes/Default/users/root.plist" AND key = "passwd" AND length(value) > 1;