add_filter before homepage loop

Hello everyone,

I’m trying to add a custom filter with a plugin I’m creating to show a box on the front page, just before the Posts loop, but after the header. Is there a hook for that? I’m searching for 4 hours now and I couldn’t find the hook I’m looking for.
This is my code:

function norilsk_filter($content) {
	if (is_single())
		return $content.box1().style();
	elseif (is_home())
		return $content.box2().style();
	else
		return $content;
}
add_filter('comments_template','norilsk_filter');
add_filter('the_header','norilsk_filter');