Our account could have been hacked

Hi I think our jotform has been hacked some of our exhibitors have been sent spam emails from anbetung@radiohoreb.de can you advise

Hello,

We are sorry for the inconvenience you have.

As far as I checked our email logs in our Admin system, I couldn't find any entry related to anbetung@radiohoreb.de email address.

It seems that you can reach your account. How did you understand that your Jotform Account has been used without your knowledge? Could you please give us further detailed information regarding the issue? Did someone send you an email regarding your password has changed? 

Thanks in advance.

Moreover, Please check your activity logs of your account as you can see in the following guide: https://www.jotform.com/help/370-How-to-View-Your-Account-Activity-Logs 

If you see different IP address that logins to your account, please change your password.

Thank you.