Exploring HackTheBox Mist: A Cybersecurity Challenge for Ethical Hackers

In the world of cybersecurity, hands-on challenges serve as one of the best ways to enhance skills and deepen knowledge. HackTheBox has been a popular platform for ethical hackers to hone their expertise through various challenges and machines. Among these, the “Mist” machine has garnered attention for its intricate layers of cybersecurity challenges. This article will guide you through some methodologies and techniques employed in conquering the Mist challenge, emphasizing ethical hacking and security learning.

Initial Reconnaissance: Nmap Scanning

The first step in any penetration test or ethical hacking engagement is reconnaissance. In the case of the Mist machine, we initiate this process using the Nmap tool. Starting the Nmap scan reveals crucial information, including open ports and the services running on them. As we probe deeper into this system, we may notice a service running a vulnerable version of pluck, which sets the stage for further exploration.

Vulnerability Discovery: CVE-2024-9405

Upon identifying the service, the next logical step is to investigate known vulnerabilities. In our findings, we delve into CVE-2024-9405, a file disclosure vulnerability that allows an attacker to glean sensitive information from the server. Understanding this vulnerability is vital, as it presents an opportunity to exploit the weaknesses of the target system.

Gaining Initial Access

After assessing the potential vulnerabilities, we discover a backup password. With this newfound information, we attempt to crack the password and gain access by uploading a malicious plugin. This plugin serves as a foothold into the system, allowing us to execute further maneuvers and escalate privileges.

Remote Code Execution (RCE) and Bypassing Defenses

With initial access established, the next phase involves obtaining Remote Code Execution (RCE). We face the challenge of a defense mechanism: Windows Defender is blocking our attempts to establish a reverse shell. To overcome this barrier, we obfuscate our command, a critical skill for any ethical hacker. This adaptation not only showcases ingenuity but also the persistent nature required to succeed in penetration testing.

Utilizing Malicious LNK Files

Our explorations lead us to create a malicious LNK file, designed to drop a shell upon execution. This method exemplifies the various techniques hackers utilize to gain persistent access. By crafting a file that appears benign, we trick users into executing it, granting us access as the user BrandonKeywarp.

Advanced Enumeration: BloodHound Setup

Once inside the system, it’s time to gather further intelligence. Setting up the BloodHound Community Edition enables us to visualize and understand the Active Directory structure better. Fixing any bugs, such as images not displaying, allows us to proceed with our analysis seamlessly. Utilizing BloodHound reveals various certificate templates we can enroll in, paving the way for further exploits.

Discovering Defender Exclusions from Event Logs

During our enumeration phase, we review the event log for Event ID 5007, which provides insights as a low privileged user. This information leads us to discover Defender exclusions, which can be leveraged for further attacks.

Credential Harvesting: NTLM Relay and Rubeus

Armed with knowledge from our reconnaissance, we use Certify to request a certificate, followed by employing Rubeus to execute a Pass-the-Ticket attack. This approach allows us to capture NTLM hashes from users, highlighting the importance of understanding authentication mechanisms within a network.

Executing NTLM Relay Attacks

Next, we explain our planned NTLM Relay attack. By installing a specialized version of Impacket, we configure our toolset to forward connections to the domain controllers’ LDAP (Lightweight Directory Access Protocol). Utilizing tools like PetitPotam with acquired hashes enables us to authenticate and gain further access.

Exploiting Service Accounts

As we dig deeper into the system, we identify a keypass database in “Sharon’s” directory. After cracking this database, we discover that the Service Accounts can grant specific permissions. By leveraging a chain of permissions, we explore the capabilities of accounts such as SVC_CA.

Achieving Administrative Privileges

Utilizing tools like Certipy, we create a certificate within ManagerAuthentication, allowing us to place ourselves within the Certificate Managers Group. This step is pivotal for further exploits, as it positions us for elevated access.

Final Steps: Dumping Credentials and Lateral Movement

As we approach the final stages, we execute an Impacket command to dump the domain controller registry, giving us access to the password for DC01. Subsequently, we perform a DCSync operation to obtain credentials for the Administrator account, completing our objective.

Conclusion

The HackTheBox Mist challenge serves as a testament to the complexities and intricacies involved in ethical hacking. Each step requires a blend of improvisation, attention to detail, and a deep understanding of security protocols. By sharing methodologies and insights, we contribute to the growth of knowledge within the cybersecurity community, promoting ethical behavior and responsible practices. As you embark on your ethical hacking journey, remember to reinforce your skills and knowledge by tackling challenges like Mist, and always prioritize learning and ethical conduct.