Find out where logins are coming from in Oracle (https://app.pluralsight.com/library/courses/oracle-performance-tuning-developers/table-of-contents)

login_origin.sql

select username, osuser, program, module,
    machine, process,
    count(1) as login_count
from v$session
where type = 'USER'
group by username, osuser, program, module,
    machine, process;