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Introduction:
Many organizations clinging to legacy Group Policy Objects (GPOs) and Group Policy Preferences (GPP) for printer mapping are unknowingly maintaining significant attack surfaces. Modernizing to Microsoft Intune is not just an operational efficiency play; it is a critical cybersecurity hardening exercise that eliminates antiquated protocols and reduces credential exposure.
Learning Objectives:
- Understand the specific cybersecurity vulnerabilities inherent in traditional GPO/GPP printer deployment.
- Learn how to export, analyze, and decommission legacy printer GPOs to reduce attack vectors.
- Master the implementation of a secure, cloud-native printer deployment strategy using Microsoft Intune.
You Should Know:
1. Identifying and Exporting Legacy Printer GPOs
The first step to modernization is a full inventory of existing policies. This is done using PowerShell on a domain controller or a management workstation with the Group Policy module.
Get-GPO -All | Where-Object { $_.DisplayName -like "printer" } | Export-GPO -Path "C:\GPOBackup"
Step-by-step guide: This PowerShell command queries all GPOs in the domain, filters for those with “printer” in the name, and exports them to the specified directory for analysis. This creates a backup and allows you to review the configured settings, which often contain scripts or credentials in SYSVOL that are vulnerable to attack.
2. Auditing GPP for Stored Credentials
Group Policy Preferences famously stored credentials in a crackable format within the SYSVOL share. Use this PowerShell command to hunt for these vulnerable files.
Get-ChildItem -Path "\$env:USERDNSDOMAIN\SYSVOL" -Recurse -Filter "Groups.xml" | ForEach-Object { [bash]$xml = Get-Content $<em>.FullName; if ($xml.Group.Preferences.Properties.password) { $</em>.FullName } }
Step-by-step guide: This script recursively searches all `Groups.xml` files in the SYSVOL share. These files are used by GPP. It then checks each file to see if it contains a password property and outputs the file path if found. Any discovered files represent a critical vulnerability, as the contained cPassword can be easily decrypted.
3. The Rock My Printers Export Tool
Nicklas Ahlberg’s ‘Rock My Printers’ tool is essential for migration. It must be downloaded from the official, verified source to avoid supply-chain attacks.
irm "https://github.com/ahlberg/rock-my-printers/raw/main/RockMyPrinters.ps1" -OutFile "RockMyPrinters.ps1" Get-ExecutionPolicy Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope Process .\RockMyPrinters.ps1 -ExportOnly -Path "C:\PrinterExport"
Step-by-step guide: This uses `irm` (Invoke-RestMethod) to securely download the script from its official GitHub repository. Before execution, check your PowerShell execution policy. Temporarily setting it to `RemoteSigned` for the current process allows you to run the locally downloaded script. The `-ExportOnly` parameter extracts your current printer configurations for analysis before a full migration.
4. Building a Secure Intune Win32 App Package
Printers are deployed in Intune as Win32 apps. Use the Microsoft Win32 Content Prep Tool to create a secure, encrypted package.
IntuneWinAppUtil.exe -c "C:\PrinterPackageSource" -s "DeployPrinter.ps1" -o "C:\IntunePackages" -q
Step-by-step guide: This command packages the source files (including your deployment script and resources) into an `.intunewin` file. The `-q` flag runs the tool quietly. The resulting file is encrypted and uploaded to Intune, ensuring the integrity and confidentiality of your deployment package during distribution.
5. Creating the PowerShell Deployment Script
The core of the Intune deployment is a robust PowerShell script that maps the printer without exposing credentials.
$PrinterName = "Finance-Printer"
$PrinterIP = "10.10.10.100"
$DriverName = "Generic / Text Only"
try {
Add-PrinterPort -Name $PrinterIP -PrinterHostAddress $PrinterIP
Add-PrinterDriver -Name $DriverName
Add-Printer -Name $PrinterName -PortName $PrinterIP -DriverName $DriverName
Write-Output "Printer $PrinterName installed successfully."
exit 0
}
catch {
Write-Error $_.Exception.Message
exit 1
}
Step-by-step guide: This script defines variables for the printer details. It uses a `try/catch` block for error handling. It first creates a standard TCP/IP port, adds the necessary driver, and then installs the printer using the port and driver. It exits with code 0 on success or 1 on failure, which Intune uses to report installation status.
6. Deploying the Package in Microsoft Intune
Within the Microsoft Intune admin center, navigate to Apps > Windows > Add > Win32 app. Upload the `.intunewin` file. For the Install command, enter:
powershell.exe -ExecutionPolicy Bypass -File DeployPrinter.ps1
Step-by-step guide: The `-ExecutionPolicy Bypass` is crucial as it ensures the script runs regardless of the local machine’s policy, a common hurdle in Intune deployments. Configure the Detection rules to use a custom script that checks for the printer’s existence (Get-Printer -Name $PrinterName -ErrorAction SilentlyContinue) to ensure accurate reporting.
7. Implementing Conditional Access for Enhanced Security
Post-migration, leverage Intune’s Conditional Access to enforce security policies. Create a new policy in the Azure portal under Security > Conditional Access.
Step-by-step guide: Target the policy to “All users” or a specific group. Under Cloud apps or actions, select “Microsoft Azure Management.” Under Conditions, configure Device state to include “Require device to be marked as compliant.” This ensures that only managed, secure, and compliant devices—ones that have successfully received your Intune policies—can access critical management APIs, locking down your environment.
What Undercode Say:
- Eliminating SYSVOL is a Top Priority: The decryption of GPP passwords (MS14-025) remains a trivial task for attackers. Any remaining GPP items are low-hanging fruit for privilege escalation and lateral movement.
- The Cloud-Native Security Advantage: Intune deployment via Win32 app uses encrypted channels and requires device compliance, removing the need for legacy, vulnerable protocols like SMB to SYSVOL and Kerberos-based authentication for policy retrieval, significantly shrinking the organization’s attack surface.
The persistence of legacy GPO/GPP for mundane tasks like printer mapping is a symptom of technical debt with direct security consequences. It represents an infrastructure stuck in an era with weaker security assumptions. Modernizing this single use case forces a reckoning with stored credentials, open network shares, and unencrypted authentication flows. The shift to Intune is not merely a cloud migration; it is a proactive threat mitigation strategy that dismantles old vulnerabilities while enforcing a zero-trust posture through device compliance. The operational benefits of faster logons are merely a bonus compared to the profound security uplift achieved.
Prediction:
The continued scrutiny of on-premise Active Directory and its associated protocols by threat actors will make legacy GPO/GPP deployment a primary initial access and lateral movement vector in the next 12-18 months. Organizations that fail to modernize these workflows will be disproportionately targeted in ransomware campaigns, as automated attack tools will readily exploit these known weaknesses. The shift to cloud-native management is inevitable and will become a baseline requirement for cyber insurance policies and regulatory compliance frameworks.
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IT/Security Reporter URL:
Reported By: Andreas Hartig – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
