How to stop this hacker?

[tipoboy]

change your FTP and Cpanel passwords, also change your database password via your Cpanel and config.php.

As nexy suggests WAY to many hacks, if you only use 10 at a time, why not uninstall reinstall as you desire?

Are these accounts active accounts or inactive accounts?

Also double check that you are the only super admin in the config.php and via the admincp