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Execution via local SxS Shared Module

Identifies the creation, change, or deletion of a DLL module within a Windows SxS local folder. Adversaries may abuse shared modules to execute malicious payloads by instructing the Windows module loader to load DLLs from arbitrary local paths.

Rule type: eql
Rule indices:

  • winlogbeat-*
  • logs-endpoint.events.file-*
  • logs-windows.sysmon_operational-*
  • endgame-*
  • logs-m365_defender.event-*
  • logs-sentinel_one_cloud_funnel.*
  • logs-crowdstrike.fdr*

Rule Severity: medium
Risk Score: 47
Runs every:
Searches indices from: now-9m
Maximum alerts per execution: ?
References:

Tags:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Tactic: Execution
  • Data Source: Elastic Endgame
  • Data Source: Elastic Defend
  • Data Source: Sysmon
  • Data Source: Microsoft Defender for Endpoint
  • Data Source: SentinelOne
  • Data Source: Crowdstrike
  • Resources: Investigation Guide

Version: ?
Rule authors:

  • Elastic

Rule license: Elastic License v2

The SxS DotLocal folder is a legitimate feature that can be abused to hijack standard modules loading order by forcing an executable on the same application.exe.local folder to load a malicious DLL module from the same directory.

file where host.os.type == "windows" and file.extension : "dll" and
  file.path : (
    "C:\\*\\*.exe.local\\*.dll",
    /* Crowdstrike specific condition as it uses NT Object paths */
    "\\Device\\HarddiskVolume*\\*\\*.exe.local\\*.dll"
  )

Framework: MITRE ATT&CK