Countercept Agent for Windows – 2026-01-05 – Ultralight Core update

The update is related to the Countercept Agent’s Ultralight Core. Ultralight Core provides low-level functionality such as file hash calculation as part of the agent’s reporting of endpoint activity.

Product Name: Countercept Agent for Windows – Ultralight Core

Version: 2.1.21134

Pilot Availability: 07/01/2026

General Availability: 14/01/2026

Predecessor: 2.1.21067

Release Purpose:

• General maintenance

Customer Action Required:

• The Operating System should be Azure Code Signing (ACS) compliant to receive this update. See
  
  https://community.withsecure.com/en/kb/articles/29714-changes-in-support-on-microsoft-windows-minimum-patch-level
  
  
  for more details.
  Any endpoints which are not ACS-compliant will continue to run the older version of the Ultralight Core (2.1.16183).

Name Changes:

• No changes to file, process, or service names.

Files Updated:

• CapricornScanner.exe
• fshoster64.exe
• fsulgk.sys
• install.exe
• uninstall.exe

New Features and Enhancements:

• N/A

General Maintenance:

• General maintenance of functionality not utilized by Countercept.

OS Support:

• Windows 10, 11
• Windows Server 2012, 2012 R2, 2016, 2019, 2022, 2025