There seems to be a hack on some steemconnect apps that lets users downvote @haejin. I would advise to check your votes, revoke all authorisations as soon as possible and change your password.
you can use https://steemd.com/@yourusername to find out who has access to your account and revoke access using https://v2.steemconnect.com/apps/authorized in case
I have posted on the @heajin issue before and have been rather critical of certain behaviours on steem, but hacking others peoples accounts to downvote is going one step to far!
Update: The compromised app seems to be Utopian. It has been disabled for now. If you find any votes you did not make, you can manually undo them.