My emergency password reset plugin will regenerate every user’s password and email it to them. If you have been hacked, I advise you change all the SALTS in wp-config.php, which forces all users to log out too. WordPress.org provides a tool to generate new SALTS.
To us my bulk emergency password reset and email plugin…
1) Download the emergency-password-reset at wordpress.org plugin
2) Upload the zip file to your plugins directory and activate.
3) If you are and administrator you can click on “Reset all Passwords” – the plugin will generate new more secure passwords and let all the users know.
Hope you find it useful