Sunday, June 29, 2025

Red Team Simulation: Active Directory Pentest

 




Introduction

In this project, I conducted a full-scope Active Directory penetration test against a simulated enterprise environment to emulate a real-world attacker. The objective was to identify and exploit common AD misconfigurations, privilege escalation paths, and authentication flaws that could lead to full domain compromise.

Read the report here


Assessment Overview

The penetration test simulated an attacker who gains initial access to an internal Windows workstation. From there, I used various techniques to pivot through the network and escalate privileges within the domain.

Key techniques used:

  • Credential dumping via Mimikatz

  • Pass-the-Hash (PTH) and Kerberoasting

  • AS-REP roasting

  • Abuse of DCSync rights

  • Golden Ticket attack using compromised krbtgt hash


Key Attack Paths Discovered

1. Credential Dumping + Pass-the-Hash

After gaining local admin on a Windows 10 machine, I used Mimikatz to dump hashes and perform a Pass-the-Hash attack to impersonate a Domain Admin.

Recommendation: Implement Local Admin Password Solution (LAPS) and disable unnecessary local admin access.


2. AS-REP Roasting

I identified user accounts with "Do not require Kerberos pre-authentication" enabled. This allowed me to request and crack AS-REP hashes to retrieve plaintext passwords.

Recommendation: Disable the pre-auth exemption using PowerShell:
Get-ADUser -Filter {DoesNotRequirePreAuth -eq $True}


3. Kerberoasting

Using a standard domain user, I requested service tickets (TGS) for SPNs and cracked the hashes offline using John the Ripper with rockyou.txt.

Recommendation: Use strong, randomly generated passwords for service accounts, especially those tied to SPNs.


4. Golden Ticket Attack

With the krbtgt hash obtained via DCSync, I generated a forged TGT (Golden Ticket) and authenticated to the domain controller as any user.

Recommendation: Reset the krbtgt account twice and monitor for unusual Kerberos activity via event logs.


Tools Used

  • Mimikatz

  • Impacket

  • BloodHound

  • Responder

  • John the Ripper

  • CrackMapExec

  • SharpHound

  • hashcat


What I Learned

This project sharpened my hands-on skills in Active Directory exploitation, including lateral movement, persistence, and credential-based attacks. I also learned how to document attack chains, map BloodHound paths, and provide actionable remediation steps.


Conclusion

This AD penetration test highlights how common misconfigurations—like weak service account passwords or overly permissive ACLs—can be chained to compromise an entire domain. By addressing these gaps, organizations can significantly reduce their exposure to internal threats.

No comments:

Post a Comment

The API Vulnerabilities I Keep Finding in Web App Pen Tests (With Step-By-Step Testing)

Modern web applications depend heavily on backend APIs, yet these APIs are often the least tested and most vulnerable part of the attack sur...