[Ettercap filters]

Yeah, tried it on multiple http websites and with internet explorer. I used nano /proc/sys/net/ipv4/ip_forward and changed it manually but that doesn't make a difference. Thanks again for the response though

[Ettercap filters]

Thank you for the response but if you're referring to including this line of code 

if (ip.proto == TCP && tcp.dst == 80) {
   if (search(DATA.data, "Accept-Encoding")) {
      replace("Accept-Encoding", "Accept-Rubbish!"); 
	  # note: replacement string is same length as original string
      msg("zapped Accept-Encoding!\n");
   }

I got the same results. Perhaps I should include more details. I'm running Kali, My ettercap is version 0.8.2, ip_forwarding is set to 1 and ettercap, when I run this code, tells me the filter has run however, no changes occur to the target computer. Any ideas on what the problem could be?

[Ettercap filters]

Followed the instructions on this site perfectly: https://cranklin.wordpress.com/2011/10/13/prank-hacking-your-co-workers-for-fun-2/

[Ettercap filters]

Here is the filter I'm using: 

if (ip.proto == TCP && tcp.src == 80) {
replace("img src=", "img src=\"http://www.cranklin.com/mickey.png\" ");
replace("IMG SRC=", "img src=\"http://www.cranklin.com/mickey.png\" ");
msg("Filter Ran.\n");
}

Everything seems to be working fine and no errors are popping up but when I go onto the internet on my host computer nothing seems to change.

[Ettercap filters]

Noob here.

Been trying to run some ettercap filters through my virtual machine while ARP-poisoning my host computer.