Potential DLL Sideloading Of MsCorSvc.DLL

Title: Potential DLL Sideloading Of MsCorSvc.DLL
Status: test
Description:Detects potential DLL sideloading of "mscorsvc.dll".
References:
  -https://hijacklibs.net/entries/microsoft/built-in/mscorsvc.html
Author: Wietze Beukema
Date: 2024-07-11
modified:2025-02-26
Tags:

• -'attack.privilege-escalation'
• -'attack.persistence'
• -'attack.execution'
• -'attack.stealth'
• -'attack.t1574.001'

Logsource:

• product: windows
• category: image_load

Detection:
  selection:
    ImageLoaded|endswith: '\mscorsvc.dll'
  filter_main_generic:
    ImageLoaded|startswith:
      -'C:\Windows\Microsoft.NET\Framework\'
      -'C:\Windows\Microsoft.NET\Framework64\'
      -'C:\Windows\Microsoft.NET\FrameworkArm\'
      -'C:\Windows\Microsoft.NET\FrameworkArm64\'
      -'C:\Windows\WinSxS\'

  condition:selection and not 1 of filter_main_*
Falsepositives:
  -Legitimate applications loading their own versions of the DLL mentioned in this rule.
Level: medium