You must ensure you have a decent password and to change it frequentl.
If Plesk is your control panel of choice for your dedicated hosting The below is how you achieve this:
Login to Plesk
Go to “Domain Administrator”.
You now get all of your domain’s preferences as they are seen by Plesk.
look for the boxes titled:
New Password
Confirm Password
Type your new password into the “New Password” text box.
It should be a 6-8 alpha-numeric password. Do not include your user name or anything that could be guessed.
Retype your password in the Confirm Password text box
Go to bottom of page & click the OK button.
To change your FTP password, go back to the main Plesk start page and click on “Setup” under “Hosting”.
Type in your 6-8 alpha-numeric password into the New FTP Password and Confirm Password boxes scroll down and hit the OK button
Your Plesk powered account has new passwords