prncnfg.vbs - Windows Print Configuration Script

Category: System-EXE-Files | Date: 2025-03-03

prncnfg.vbs - Windows Print Configuration Script

Overview

prncnfg.vbs is a Visual Basic Script (.vbs) file located in the %SystemRoot%\System32\Printing_Admin_Scripts\<language code> directory (e.g., C:\Windows\System32\Printing_Admin_Scripts\en-US) of Windows operating systems. It's one of several scripts provided by Microsoft for managing printers and print servers from the command line. prncnfg.vbs specifically focuses on configuring existing printer settings, including ports, drivers, and shared printer properties. It does not install new printers (use prnmngr.vbs for that).

Origin and Purpose

prncnfg.vbs is a legitimate Microsoft-provided script. It is part of the Windows printing subsystem and is used by administrators to automate printer configuration tasks, especially in enterprise environments or when managing multiple print servers. It leverages the Windows Management Instrumentation (WMI) provider for printing (Win32_Printer).

Functionality

prncnfg.vbs allows you to:

  • Change printer configurations: Modify settings like printer name, driver, port, shared status, share name, location, comment, and various other advanced printer properties.
  • Get printer configurations: Retrieve detailed information about a specific printer, including all its current settings.
  • Rename a printer.
  • Set a printer as the default printer.

It cannot:

  • Install new printers. Use prnmngr.vbs to add, delete and list printers.
  • Manage print queues directly (pause, resume, purge). Use prnqctl.vbs for that.
  • Manage print jobs. Use prnqctl.vbs

Is it a Virus?

No, prncnfg.vbs itself is not a virus. It's a legitimate system file provided by Microsoft.

Can it Become a Virus?

No, a .vbs file cannot "become" a virus in the sense of transforming itself. However, like any script file, it is theoretically possible for a malicious actor to:

  1. Replace the legitimate prncnfg.vbs with a malicious script: A virus could overwrite the legitimate prncnfg.vbs file with a malicious script that also has the .vbs extension and performs harmful actions. This would require administrator privileges.
  2. Exploit vulnerabilities: While extremely unlikely, a highly sophisticated attack could potentially leverage an unknown vulnerability in how cscript.exe (the Windows Script Host) interprets VBScript to execute malicious code through a seemingly legitimate script like prncnfg.vbs. This would be a zero-day exploit and is highly improbable.
  3. Trick users into running a malicious VBS file named similarly: Attackers may try to socially engineer a user or another script into executing a malicious VBS file, possibly giving it a name that resembles prncnfg.vbs (e.g., prncnfg_.vbs, prn-cnfg.vbs).

The vast majority of the risk comes from scenario 1 and scenario 3, where the file itself is replaced or a similarly named imposter is used.

Usage (Tool Functionality)

prncnfg.vbs is run from the command line using cscript.exe. Here's the basic syntax and common usage examples:

cscript prncnfg.vbs [options]

Or, if the file path is already set, you can run the file from the command line directly:

prncnfg.vbs [options]

Key Options (not exhaustive):

  • -g: Get printer configuration. Requires -p.
  • -t: Change printer configuration. Requires -p and at least one other configuration option.
  • -x: Rename printer. Requires -p and -z.
  • -l: List printers. Requires -s.
  • -p <printername>: Specifies the printer name. Required for -g, -t, and -x.
  • -s <servername>: Specifies the remote print server. If omitted, the command targets the local machine.
  • -z <newprintername>: Specifies the new printer name (used with -x).
  • -u <username>: Specifies a username for authentication (for remote servers).
  • -w <password>: Specifies the password for authentication (for remote servers).
  • +shared: share the specified printer.
  • -shared: Unshare the specified printer.
  • -m <sharename>: Specifies the share name.
  • -h <portname>: Specifies the port name.
  • -r <drivername>: Specifies the driver name.
  • -y <datatype>: Specifies the default data type.
  • -f <separatorfile>: Specifies the separator page file.
  • +published: Publish the specified printer in Active Directory.
  • -published: Do not publish the specified printer in Active Directory.
  • -i <inf file>: Specifies the .inf file for driver installation (though prncnfg.vbs is NOT for installing the driver itself). This is more relevant when used in conjunction with other scripts.
  • -o <priority>: Specifies the priority.
  • -e <start time>: Specifies the start time for availability.
  • -a <until time>: Specifies the until time for availability.
  • +keepprintedjobs: Specifies that printed jobs should be kept.
  • -keepprintedjobs: Specifies that printed jobs should not be kept.
  • -c <comment>: Specifies a comment.
  • -n <location>: Specifies the location.
  • /?: Displays help.

Examples:

  1. Get configuration of a local printer named "MyPrinter":

    cscript prncnfg.vbs -g -p "MyPrinter"

  2. Change the port of a printer named "OfficePrinter" on server "PrintServer01" to "LPT1:":

    cscript prncnfg.vbs -t -s PrintServer01 -p OfficePrinter -h "LPT1:"

  3. Rename a printer from "OldPrinter" to "NewPrinter":

    cscript prncnfg.vbs -x -p OldPrinter -z NewPrinter

  4. Share a printer named "ColorLaser" with the share name "ColorShared":

    cscript prncnfg.vbs -t -p ColorLaser +shared -m ColorShared

  5. Unshare a printer named "SharedPrinter". cscript prncnfg.vbs -t -p SharedPrinter -shared

  6. Get configuration of a remote printer named "RemotePrinter" on server "PrintSrv", using credentials:

    cscript prncnfg.vbs -g -s PrintSrv -p RemotePrinter -u MyDomain\MyUser -w MyPassword 7. Set the default printer rundll32 printui.dll,PrintUIEntry /y /n "printer name" It's worth noting that prncnfg.vbs can't set the default printer on its own. You'll typically use the rundll32 printui.dll,PrintUIEntry command for that, as shown above. prncnfg.vbs modifies the configuration of an existing printer, but setting the default is a separate operation.

Important Notes:

  • You often need administrative privileges to use prncnfg.vbs to modify printer configurations.
  • Incorrectly using prncnfg.vbs can disrupt printing services. Test changes in a non-production environment first.
  • The specific options available may vary slightly depending on the Windows version. Use cscript prncnfg.vbs /? for a full list of options on your system.
  • Always double-check printer names and server names to avoid unintended consequences.
  • It's generally recommended to use PowerShell cmdlets for printer management in modern Windows environments, as they offer more features and flexibility. However, prncnfg.vbs remains a viable option, especially for legacy systems or situations where VBScript is already in use.

Security Recommendations

  • Keep your system updated: Regularly install Windows updates to patch any potential vulnerabilities.
  • Use strong passwords and least privilege: Ensure administrator accounts have strong, unique passwords. Run commands with the minimum necessary privileges.
  • Monitor file integrity: Use file integrity monitoring tools (like System File Checker - sfc /scannow) to detect unauthorized changes to system files, including prncnfg.vbs.
  • Use antivirus software: A reputable antivirus program can help detect and prevent malicious scripts from running.
  • Be cautious of unsolicited scripts: Do not run VBScript files from untrusted sources.

By understanding the purpose and potential risks of prncnfg.vbs, administrators can use it safely and effectively to manage their printing environment. While it's not inherently malicious, like any system tool, it can be misused. Good security practices are crucial to mitigate any potential risks.