Script to find who has changed the sysadmin Password

SELECT substr(d.user_name,1,30) || '~'||substr(f.user_name,1,10)||'~'||substr(d.last_update_date,1,10) key, count(*) value
FROM apps.fnd_user d, apps.fnd_user f
WHERE
trunc(d.last_update_date) = trunc(sysdate)
and d.user_name = 'SYSADMIN'
and d.last_updated_by = f.user_id
GROUP BY substr(d.user_name,1,30) || '~'||substr(f.user_name,1,10)||'~'||substr(d.last_update_date,1,10);