Query: ATT&CK technique for XSL Script Processing
Matching passage: T1220 XSL Script Processing. Tactics: stealth. Description: Adversaries may bypass application control and obscure execution of code by embedding scripts inside XSL files. Extensible Stylesheet Language (XSL) files are commonly used to describe the processing and rendering of data within XML files. To support complex operations, the XSL standard includes support for embedded scripting in various languages. (Citation: Microsoft XSLT Script Mar 2017) Adversaries may abuse this functionality to execute arbitrary files while potentially bypassing application control. Similar to [Trusted Developer Utilities Proxy Execution](https://attack.mitre.org/techniques/T1127), the Microsoft common line transformation utility binary (msxsl.exe) (Citation: Microsoft msxsl.exe) can be installed and used to execute malicious JavaScript embedded within local or remote (URL referenced) XSL files. (Citation: Penetration Testing Lab MSXSL July 2017) Since msxsl.exe is not installed by default, an adversary will likely need to package it with dropped files. (Citation: Reaqta MSXSL Spearphishing MAR 2018) Msxsl.exe takes two main arguments, an XML source file and an XSL stylesheet. Since the XSL file is valid XML, the adversary may call the same XSL file twice. When using msxsl.exe adversaries may also give the XML/XSL files an arbitrary file extension.(Citation: XSL Bypass Mar 2019) Command-line examples:(Citation: Penetration Testing Lab MSXSL July 2017)(Citation: XSL Bypass Mar 2019) * <code>msxsl.exe customers[.]xml script[.]xsl</code> * <code>msxsl.exe script[.]xsl script[.]xsl</code> * <code>msxsl.exe script[.]jpeg script[.]jpeg</code> Another variation of this technique, dubbed “Squiblytwo”, involves using [Windows Management Instrumentation](https://attack.mitre.org/techniques/T1047) to invoke JScript or VBScript within an XSL file.(Citation: LOLBAS Wmic) This technique can also execute local/remote scripts and, similar to its [Regsvr32](https://attack.mitre.org/techniques/T1218/010)/ "Squiblydoo" counterpart, leverages a trusted, built-in W
Near-miss passage: T1134 Access Token Manipulation. Tactics: stealth, privilege escalation. Description: Adversaries may modify access tokens to operate under a different user or system security context to perform actions and bypass access controls. Windows uses access tokens to determine the ownership of a running process. A user can manipulate access tokens to make a running process appear as though it is the child of a different process or belongs to someone other than the user that started the process. When this occurs, the process also takes on the security context associated with the new token. An adversary can use built-in Windows API functions to copy access tokens from existing processes; this is known as token stealing. These token can then be applied to an existing process (i.e. [Token Impersonation/Theft](https://attack.mitre.org/techniques/T1134/001)) or used to spawn a new process (i.e. [Create Process with Token](https://attack.mitre.org/techniques/T1134/002)). An adversary must already be in a privileged user context (i.e. administrator) to steal a token. However, adversaries commonly use token stealing to elevate their security context from the administrator level to the SYSTEM level. An adversary can then use a token to authenticate to a remote system as the account for that token if the account has appropriate permissions on the remote system.(Citation: Pentestlab Token Manipulation) Any standard user can use the <code>runas</code> command, and the Windows API functions, to create impersonation tokens; it does not require access to an administrator account. There are also other mechanisms, such as Active Directory fields, that can be used to modify access tokens.