You can redirect bad 403, 404 and 500 requests to your home page using .htaccess and php.
In Windows, open notepad and enter the lines:
ErrorDocument 403 /badrequest.php
ErrorDocument 404 /badrequest.php
ErrorDocument 500 /badrequest.php
Next save the text doc to your hard drive as “Save as type: All Files(*.*)” .htaccess.
Next, upload the .htaccess file to your website’s root directory using filezilla, or another ftp program.
Next create a php file with the following code and save it to the root directory of your website as badrequest.php.