nginx-block.conf

server {
    ## Block user agents
    set $block_user_agents 0;

    # Common bandwidth hoggers and hacking tools.
    if ($http_user_agent ~ "libwww-perl") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "Go-http-client") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "python-requests") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "masscan") {
        set $block_user_agents 1;
    }
    if ($http_user_agent ~ "masscan") {
        set $block_user_agents 1;
    }
    if ($block_user_agents = 1) {
        return 403;
    }
}