need urgent help , i'm under spam attack

someone is using the form on my site to send me hundreds of emails
what can i do , i need your help

 

Quickest probable to block their ip from accessing your site at all.

 

$badStrings = array("Content-Type:",
                     "MIME-Version:",
                     "Content-Transfer-Encoding:",
                     "Bcc:",
                     "Cc:",
                     "To:");

foreach($_POST as $k => $v){
   foreach($badStrings as $v2){
       if(strpos(strtolower($v), strtolower($v2)) !== false){
           header("HTTP/1.1 403 Forbidden");
           exit();
       }
   }
}

PHP:

If your server supports PHP, then add this piece of code to the top of form processing script. It will validate the POST data against the bad header injection strings and exit with 403 forbidden status code if it is found to be header injection attack.

Hope it helps.

 

i am using the form presented by my host

so i'm practically putting the form code in an html file ....

is the code given can be put in this html file or should
it be put in the processing file used by my host

....

 

You should place this code in your PHP script and not in HTML.

I guess your form processing script must be written in PERL. In such case you will need to put a similar perl code which performs the same action. Otherwise you should modify the processing script to php.

If it is a simple contact us form, please let me know. I can help you upto some extend.

 

yes indeed it is a simple contact us form

 

Add a captcha (image verification script) to your form.

 

i've done this for some time
then i guess the spammer went so i've put it again
now i'm simply trying to find ways to prevent it from hapenning again