Bettercap/Failed DNS Spoofing Attack 2

From charlesreid1

Revision as of 07:25, 25 August 2016 by Admin (talk | contribs) (→‎More ideas)

Second experiment, now that I know I need to be running an ARP spoofing attack simultaneous with the DNS attack.

Configure DNS File

We configured this attack to hijack requests for charlesreid1.com: 

# Empty lines or lines starting with # will be ignored.

local .*charlesreid1\.com

Run ARP+DNS Attack

Start by running the Bettercap command: 

bettercap -I wlan1 -O bettercap_extrabacon.log -S ARP -X \
    --gateway 192.168.0.1 --target 192.168.0.7 \
    --dns extrabacon.conf --dns-port 53 \
    --httpd --httpd-path ./pub

This sets up the ARP poisoning, and runs the DNS spoofing on port 53. It runs an HTTP host to host the NOPE page.

Now, we have the sheep being DNS-spoofed. Let's test it out.

Testing It Out

On the sheep, I visit an insecure site, but NOT one that is in the DNS configuration file: http://nytimes.com

Immediately the sheep shows the NOPE page. It's not supposed to.

I visit another insecure site, NOT one that is in the DNS configuration file: http://nba.com

Again, the sheep shows the NOPE page. It's not supposed to.

I visit a secure site: https://dropbox.com.

The Dropbox site loads as expected - no redirects, no issues.

I visit another secure site: https://en.wikipedia.org

Wikipedia loads as expected.

I visit an insecure site: http://mlb.com

The sheep shows the NOPE page. It's not supposed to.

This attack is not working as expected.

It's possible my DNS cache is crusty.

Packet Traffic

Watching the packet traffic, here's what I'm seeing for the requests for insecure sites (e.g., nytimes):

  • Sheep types "nytimes.com" into browser
  • DNS request packet for nytimes.com server, addressed to gateway, arrives at attacker
  • Attacker forwards DNS request to Google public DNS server, 8.8.8.8
  • Google public DNS server responds to attacker with 170.149.159.130
  • Attacker, masquerading as gateway, sends DNS query response to sheep

Watching the packet traffic flowing, I can actually see from inspecting the DNS packets that the sheep should not be redirected to the NOPE page. And yet... the sheep is still going there, for some reason.

Firewall

Well duh, it's my firewall rule. All the packets going through port 80 are being redirected to port 8081.

Without the Firewall

On the sheep, I visit a secure page, dropbox.com:

No spoofing happening.

On the sheep, I visit a secure page, sourceforge.net:

No spoofing happening.

On the sheep, I visit an insecure page, battle.net (definitely not in the DNS cache):

I see the NOPE page. So, things are still not working correctly.

Packet Traffic Again

Inspecting packet traffic again, for the battle.net request, I can see the DNS request packet from the sheep (192.168.0.7) to the gateway (192.168.0.1), which is intercepted by the attacker. The attacker then forwards the DNS request to Google's public DNS servers, gets a response, and forwards the response along to the sheep (spoofing the gateway).

I can see the packet with the DNS query response, which contains the battle.net server IP address, 24,105.29.40, but again, the sheep is doing something else that leads it to connect instead to the HTTP server on the attacker.

Cache Problem Again

Okay, proof this is (also?) a cache problem:

When the DNS spoofing from the attacker stops, and has been stopped for a good 10 minutes, I point the sheep to nytimes.com, and what do I see?

An empty black background, and a missing NOPE graphic.

Re-Running Adjusted Attack

Okay: have adjusted the attack somewhat to test things out.

Running ARP poisoning attack with bettercap.

Hijacking DNS but using empty configuration file.

Results: when I visit HTTP sites in the browser, they break: "Unable to connect." When I visit HTTPS sites in the browser, they work just fine.

Third Machine

Now trying to use a third machine (on the local network) to serve up the static content. I get the feeling the httpd flag is setting a firewall rule that's redirecting all HTTP traffic to that port.

Nope. That doesn't work either.

More ideas

More ideas? Maybe packets on port 80 aren't allowed through and therefore aren't forwarded.

Well, it changed the problem, at least. I tried opening port 80 with a rule like this: 

iptables -A INPUT -p tcp --dport 80 -j ACCEPT

on the attacker machine. Now, the problem has shifted to the DNS query responses getting "destination unreachable (port unreachable)".

I KNOW I'm close, I'm just... not getting the pieces to line up correctly.

dnsspoof

Trying dnsspoof instead.

Setting up an ARP Poisoning attack with bettercap... 

$ dnsspoof -i wlan1 -f extrabacon.conf
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