Msxsl.EXE Execution

Status: test
Severity: medium
Log source: category process_creation, product windows
Author: Timur Zinniatullin, oscd.community
Source: github.com/SigmaHQ/sigma

Detects the execution of the MSXSL utility. This can be used to execute Extensible Stylesheet Language (XSL) files. These files are commonly used to describe the processing and rendering of data within XML files. Adversaries can abuse this functionality to execute arbitrary files while potentially bypassing application whitelisting defenses.

Known false positives

Msxsl is not installed by default and is deprecated, so unlikely on most systems.

MITRE ATT&CK coverage

Tactic	Techniques
Stealth	`T1220` XSL Script Processing

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Security-Auditing	Event ID 4688: A new process has been created.

Rule body

title: Msxsl.EXE Execution
id: 9e50a8b3-dd05-4eb8-9153-bdb6b79d50b0
status: test
description: |
    Detects the execution of the MSXSL utility. This can be used to execute Extensible Stylesheet Language (XSL) files. These files are commonly used to describe the processing and rendering of data within XML files.
    Adversaries can abuse this functionality to execute arbitrary files while potentially bypassing application whitelisting defenses.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1220/T1220.md
    - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Msxsl/
author: Timur Zinniatullin, oscd.community
date: 2019-10-21
modified: 2023-11-09
tags:
    - attack.stealth
    - attack.t1220
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\msxsl.exe'
    condition: selection
falsepositives:
    - Msxsl is not installed by default and is deprecated, so unlikely on most systems.
# Note: If you levreage this utility please consider adding additional filters. As this is looking for "any" type of execition
level: medium

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    Image|endswith: '\msxsl.exe'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Image`	ends_with	`\msxsl.exe` corpus 6 (sigma 6)	`field:"Image" kind:ends_with value:"\msxsl.exe"`