It should also be before the closing Body tag also if it is legit and you want it displayed on the page.
I couldn't recall if is a footer tag, having done a bit of a google there is a new footer tag in the HTML5 standards. All my web design was done in HTML4 standard. http://www.w3schools.com/tags/html5_footer.asp
, this w3schools site also seems a very good source of information, http://www.w3schools.com/default.asp
Frontpage, depending on what version may or may not be standards compliant, given that it is an M$ tool it used to have proprietary html tags that only worked with IE. So if you are serious about this you should ensure you have an html application that is wc3 compliant.
Yahoo may be getting its return in the price of free hosting, if you are paying for hosting I would be very p***ed off about it editing 'my' site. So I would be talking to Yahoo about the code being tagged to your page as shown in this topic.
I would also be complaining about my site being hacked and what were they going to do about this, their hosting software should really offer protection against this type of thing. You should also change your password you use to log on to edit the site to something much stronger.