Is it possible to add “/” as a stopword?

Yes, that’s a very common hacker attack, I see a lot of that on many sites. It doesn’t work, it’s just annoying.

You can’t use / as a stopword, but you can do this:

add_filter( 'pre_get_posts', 'rlv_block_search' );
function rlv_block_search( $query ) {
    if ( ! empty( $query->query_vars['s'] ) ) {
        if ( stripos( $query->query_vars['s'], 'index/' ) !== false ) {
            http_response_code( 410 );
            exit();
        }
     }
}

This would make all queries with index/ in them return a “410 Gone” status message. You can also block all queries with just / in them with stripos( $query->query_vars['s'], '/' ), but I can see legitimate users use a slash in their searches sometimes, so this kind of block is probably too dramatic.

Thank you Mikko. I prefer not to modify the code, just afraid of break something…

Is it possible to add an option for this attack? Thanks.

Relevanssi Premium has a spam blocking feature where you can enter keywords. I have the /think keyword blocked on one of my sites to stop this exact problem. That’s the easy way, but it’s a premium feature.

Thank you!