Signed Script Proxy Execution: PubPrn

Adversaries may use PubPrn to proxy execution of malicious remote files. PubPrn.vbs is a Visual Basic script that publishes a printer to Active Directory Domain Services. The script is signed by Microsoft and is commonly executed through the Windows Command Shell via Cscript.exe. For example, the following code publishes a printer within the specified domain: cscript pubprn Printer1 LDAP://CN=Container1,DC=Domain1,DC=Com.[1]

Adversaries may abuse PubPrn to execute malicious payloads hosted on remote sites.[2] To do so, adversaries may set the second script: parameter to reference a scriptlet file (.sct) hosted on a remote site. An example command is pubprn.vbs script: This behavior may bypass signature validation restrictions and application control solutions that do not account for abuse of this script.

In later versions of Windows (10+), PubPrn.vbs has been updated to prevent proxying execution from a remote site. This is done by limiting the protocol specified in the second parameter to LDAP://, vice the script: moniker which could be used to reference remote code via HTTP(S).

ID: T1216.001
Sub-technique of:  T1216
Tactic: Defense Evasion
Platforms: Windows
Permissions Required: User
Defense Bypassed: Application Control, Digital Certificate Validation
Contributors: Atul Nair, Qualys
Version: 1.1
Created: 03 February 2020
Last Modified: 01 September 2021

Procedure Examples

ID Name Description
G0050 APT32

APT32 has used PubPrn.vbs within execution scripts to execute malware, possibly bypassing defenses.[3]


ID Mitigation Description
M1040 Behavior Prevention on Endpoint

On Windows 10, update Windows Defender Application Control policies to include rules that block the older, vulnerable versions of PubPrn.[4]

M1038 Execution Prevention

Certain signed scripts that can be used to execute other programs may not be necessary within a given environment. Use application control configured to block execution of these scripts if they are not required for a given system or network to prevent potential misuse by adversaries.


ID Data Source Data Component
DS0017 Command Command Execution
DS0009 Process Process Creation
DS0012 Script Script Execution

Monitor script processes, such as cscript, and command-line parameters for scripts like PubPrn.vbs that may be used to proxy execution of malicious files.