Someone is using my account for voting.

Hi, somehow my account has been compromised. Someone is using my account to upvote posts. I have changed my password, but they can still upvote with my account. What can I do to stop this?

EDIT:
I found my answer here: https://steemit.com/steem/@sn0n/how-to-revoke-app-access-to-your-steem-account

Yay! free at last. :-D