Aliens HTB Write Up: A Step-by-Step Guide to Solving the Hack The Box Challenge

Aliens HTB Write Up pdf (HTB) is an online platform where users can test and improve their cybersecurity skills by solving challenges and hacking into virtual machines (VMs). One of these challenges is the Aliens box, which is categorized as an easy to medium-level difficulty. In this write-up, we will go through the steps to complete the challenge, from initial scanning to gaining root access.

Disclaimer: This post is purely for educational purposes. Always follow legal and ethical practices when dealing with cybersecurity challenges.

Table of Contents of Aliens HTB Write Up Scene

Introduction to Hack The Box and Aliens VM
Initial Enumeration
- Network Scanning (Nmap)
- Service Identification
Exploring and Exploiting SMB Shares
Working with FTP
Gaining Initial Foothold
Privilege Escalation
Root Access and Capture the Flag
Conclusion
FAQs

1. Introduction to Hack The Box and Aliens VM

Hack The Box provides various virtual machines that simulate real-world environments. Each machine represents a scenario where ethical hacking skills are required to identify and exploit vulnerabilities.

The Aliens VM is a challenge that incorporates multiple services and requires solid enumeration and privilege escalation skills. As an ethical hacker, your goal is to analyze the VM, find weaknesses, and eventually gain full access to the system, retrieving the flags—that prove you’ve completed the challenge.

2. Initial Enumeration

The first step in any cybersecurity challenge is to conduct proper enumeration. Enumeration is gathering information about the target machine to identify open ports, services, and potential vulnerabilities.

Network Scanning (Nmap)

We begin with a basic Nmap scan to discover open ports and services on the Aliens machine. Nmap is a network scanner that can provide insights into running services, their versions, and other critical information.

bashCopy codenmap -sC -sV -oN aliens_initial_scan 10.10.10.X

In this command:

-sC uses default Nmap scripts for deeper scanning.
-sV attempts to determine the version of the running services.
-oN saves the scan results in a file for later reference.

Scan Results:

swiftCopy codePORT    STATE SERVICE    VERSION
21/tcp  open  ftp        vsftpd 3.0.3
22/tcp  open  ssh        OpenSSH 7.9 (protocol 2.0)
139/tcp open  netbios-ssn Samba smbd 3.X - 4.X workgroup
445/tcp open  netbios-ssn Samba smbd 3.X - 4.X workgroup

From the scan, we can see the following:

Port 21: FTP service is running, allowing anonymous login.
Port 22: SSH is open, which might be useful later.
Port 139 and 445: Samba file-sharing services are active.

This gives us a good starting point for further exploration.

3. Exploring and Exploiting SMB Shares

Samba, a file-sharing service, is accessible on ports 139 and 445. We can use the smbclient tool to investigate the available shares.

bashCopy codesmbclient -L 10.10.10.X

This command lists the shared folders (shares) on the target machine. The output might look like this:

mathematicaCopy codeSharename       Type      Comment
---------       ----      -------
public          Disk      Public Share

The shared named public looks interesting. We can connect to this share and explore its contents:

bashCopy codesmbclient //10.10.10.X/public

Once connected, we can use basic commands like ls to list files and get download files of interest.

Finding Useful Files

After exploring the public share, we might find some files that could contain useful information. For example, a file named users.txt could give us hints about potential usernames, or a file with scripts might help in privilege escalation.

4. Working with FTP

FTP (File Transfer Protocol) is running on the Aliens machine, and according to our Nmap scan, anonymous login is allowed. This means we can log in without providing a username or password:

bashCopy codeftp 10.10.10.X

After logging in as anonymous, we can list the available files:

bashCopy codels

We might find files such as messages.txt, which could contain clues for our next step.

5. Gaining Initial Foothold

After gathering information from FTP and SMB, the next task is to gain a foothold in the system. A foothold means gaining initial access to the machine, typically with limited privileges.

Exploiting Vulnerabilities

Using the gathered information, we can search for vulnerabilities that correspond to the services running on the machine. In this case, a vulnerable Samba version might allow us to execute remote commands.

We can use Metasploit to attempt an exploitation of Samba. Start the Metasploit framework with the following command:

bashCopy codemsfconsole

Search for available exploits for the Samba service:

bashCopy codesearch samba

Once we identify the correct exploit, we can configure it with the appropriate target IP and attempt to gain access.

6. Privilege Escalation

Gaining a foothold in the system is just the beginning. You’ll usually have limited access, such as a low-privilege user account. The next step is to escalate privileges to gain root access.

Finding Vulnerabilities for Privilege Escalation

One common method for privilege escalation is to search for files with setuid or setgid permissions. These files run with elevated privileges, and if misconfigured, they can allow regular users to perform actions with administrative rights.

bashCopy codefind / -perm -4000 2>/dev/null

This command lists all files with the setuid bit set, which can be used to escalate privileges.

Kernel Exploits

Sometimes, the machine might be vulnerable to kernel exploits. Using tools like LinPEAS (Linux Privilege Escalation Awesome Script), we can automate the process of finding weaknesses in the system.

Download and execute LinPEAS to analyze the system for potential privilege escalation vectors:

bashCopy codewget http://example.com/linpeas.sh
chmod +x linpeas.sh
./linpeas.sh

Review the output carefully to identify any potential vulnerabilities.

7. Root Access and Capture the Flag

Once we’ve successfully escalated privileges, we should be able to gain root access to the machine. We may exploit a vulnerable service, find a misconfigured file, or use an escalation script to do this.

After gaining root access, the final step is to capture the root flag. On Hack The Box machines, this flag is usually located in the /root directory.

bashCopy codecat /root/root.txt

This will display the root flag, marking the successful completion of the challenge.

8. Conclusion

The Aliens HTB write ups machine is a great challenge for practicing enumeration, file service exploitation, and privilege escalation. The key to solving this box lies in methodical enumeration—gathering information from FTP, SMB, and services like Samba. Once you’ve gained a foothold in the system, privilege escalation techniques such as searching for setuid binaries and leveraging kernel exploits are crucial.

Always remember that Hack The Box challenges are designed to help improve your ethical hacking skills. Solving these challenges requires patience, creativity, and a structured approach.

Everdeen Technology LLC: A Comprehensive Overview

Frequently Asked Questions (FAQs)

1. What is Hack The Box (HTB)?

Hack The Box (HTB) is an online platform that provides virtual machines (VMs) for cybersecurity enthusiasts to practice ethical hacking. It offers challenges that simulate real-world security scenarios where users identify and exploit vulnerabilities to gain access to systems.

2. What is the Aliens machine in HTB?

The Aliens machine is one of the virtual challenges available on HTB. It is rated as an easy-to-medium difficulty level and requires users to exploit multiple services to gain both user and root access. The challenge tests skills in enumeration, file-sharing service exploitation (SMB, FTP), and privilege escalation.

3. How do I start the Aliens HTB challenge?

To start the Aliens HTB challenge:

Log into your Hack The Box account.
Navigate to the Machines section and select Aliens.
Connect your VPN to HTB using the connection pack.
Begin enumeration by scanning the Aliens machine IP using tools like Nmap.

4. Why is enumeration important in hacking challenges?

Enumeration is the first and one of the most important steps in ethical hacking. It helps you gather valuable information about open ports, services, and potential vulnerabilities, providing insights into how the target system operates. Without proper enumeration, it is difficult to know where to start an attack.

5. What tools are commonly used for enumeration?

Some common tools used for enumeration in HTB challenges include:

Nmap: A powerful network scanner for identifying open ports and services.
smbclient: A tool for interacting with SMB (file-sharing) services.
ftp: For interacting with FTP services and retrieving files.
Netcat (nc): A tool for reading and writing data across network connections.

6. What are SMB and FTP in the context of HTB challenges?

SMB (Server Message Block) is a file-sharing protocol used for sharing files and folders over a network. In HTB challenges, misconfigured SMB shares may allow unauthorized access to sensitive information.
FTP (File Transfer Protocol) is a protocol used to transfer files between a client and a server. In some challenges, anonymous login to FTP may reveal critical files that help in gaining access to the machine.

7. How can I use Nmap to scan a machine?

You can use the following command to scan a machine using Nmap:

bashCopy codenmap -sC -sV -oN scan_result 10.10.10.X

This command will:

Scan the machine IP for open ports (10.10.10.X).
Use default scripts (-sC) and service version detection (-sV).
Save the output to a file named scan_result.

8. What is a foothold in ethical hacking?

A foothold is the initial, often low-privileged, access gained on a target machine. This is typically the first step after discovering a vulnerability. Once you have a foothold, the next step is to escalate privileges to gain full control (root access) over the system.

9. What is privilege escalation?

Privilege escalation is the process of gaining elevated permissions on a system after gaining a foothold. On most systems, users start with limited access. By exploiting misconfigurations, weak services, or vulnerabilities, an attacker can increase their privileges to gain administrative (root) access.

10. How do I escalate privileges on the Aliens machine?

For privilege escalation on the Aliens machine:

Look for setuid or setgid files with the following command:bashCopy codefind / -perm -4000 2>/dev/null
Analyze the output for misconfigured files or binaries that can be used to gain higher privileges.
Additionally, use tools like LinPEAS to automatically search for privilege escalation vectors.

11. What are setuid files?

Setuid (Set User ID) files are executables that allow a user to run a program with the file owner’s privileges. If not properly configured, these files can be exploited to perform actions with elevated privileges.

12. What is the root flag?

In HTB challenges, the root flag is a file located in the /root directory of the target machine. Retrieving this flag is the ultimate goal of most HTB challenges and signifies that you have successfully gained root (administrator) access to the machine.

13. How can I use Metasploit to exploit vulnerabilities?

To use Metasploit:

Start the tool with the command:bashCopy codemsfconsole
Search for exploits related to the service you are targeting. For example:bashCopy codesearch samba
Select the appropriate exploit, configure it with the target IP and necessary parameters, and run the exploit.

14. What is LinPEAS and how does it help in privilege escalation?

LinPEAS is a script that helps identify potential privilege escalation paths on Linux machines. It automates the process of searching for vulnerabilities, misconfigurations, and files that can be used to gain root access.

15. What should I do if I get stuck on an HTB machine?

If you get stuck on an HTB machine, consider the following:

Go back and recheck your enumeration. You may have missed a critical detail.
Use online resources such as forums and blog write-ups for hints and guidance (avoid directly copying solutions as you won’t learn much this way).
Experiment with different tools and techniques, and think creatively about how the system could be vulnerable.

16. Is it okay to use Metasploit on all HTB machines?

Some Hack The Box challenges restrict the use of Metasploit to encourage manual exploitation techniques. Always check the machine’s description to see if using automated tools like Metasploit is allowed.

17. How can I improve my ethical hacking skills using Hack The Box?

To improve your skills:

Start with easy or beginner machines and gradually work your way up to harder challenges.
Focus on understanding each step of the hacking process (enumeration, exploitation, and privilege escalation).
Participate in forums and discussions to learn from other users.
Document your findings and solutions to reinforce your knowledge and help others.

18. Can I work on Hack The Box challenges in teams?

Yes, Hack The Box allows team collaborations. You can form teams with other users and work together to solve challenges. This is a great way to learn from others and improve your teamwork skills.

19. What are the ethical guidelines when practicing hacking?

When practicing ethical hacking, always follow these guidelines:

Only hack machines or systems where you have explicit permission, such as platforms like Hack The Box.
Never perform unauthorized attacks on real-world systems.
Always respect privacy and confidentiality when handling sensitive information.
Use your skills to help improve security, not harm it.

20. How do I submit flags on Hack The Box?

Once you capture a flag (user or root flag), you can submit it on the Hack The Box platform. Simply navigate to the machine’s page, find the flag submission field, and enter the captured flag.