Countercept Agent for macOS 25.2 has been released to general availability (GA) on 26th of November 2025.

Release contents:

• Updated sensor with new detection capabilities
• Refreshed product icons (macOS 26 compatible)
• Discontinued support for macOS 13

Installer can be downloaded from

https://download.withsecure.com/countercept/macos/latest/WithSecure-Countercept-Agent-54880.pkg

The update is related to the Countercept Agent’s Security Cloud Core component. The Security Cloud Core component provides means for accessing WithSecure’s Security Cloud functionalities utilized by the agent’s detection components.

Product Name: Countercept Agent for Windows – Security Cloud Core

Version: 2.1.20961

Pilot Availability: 26/11/2025

General Availability: 04/12/2025

Predecessor: 2.1.20854

Release Purpose:

• General maintenance

Customer Action Required:

• N/A

Name Changes:

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

Files Updated:

• install.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

Countercept Agent for macOS 25.2 pilot release

Countercept Agent for macOS 25.2 has been released to our pilot customers on 19th of November 2025.

Release contents:

• Updated sensor with new detection capabilities
• Refreshed product icons (macOS 26 compatible)
• Discontinued support for macOS 13

Installer can be downloaded from

https://download.withsecure.com/countercept/macos/latest/WithSecure-Countercept-Agent-54880.pkg

This is a pre-announcement of Countercept Agent for macOS 25.2 which will be released to our pilot customers on 19th of November 2025.

Release contents:

• Updated sensor with new detection capabilities
• Refreshed product icons (macOS 26 compatible)
• Discontinued support for macOS 13

The update is related to the Countercept Agent’s Sensor component. The Sensor component gathers data to be analyzed in the WithSecure backend to identify any malicious activity. 

Product Name: Countercept Agent for Windows – Sensor Component

Version: 2025.3.54

Pilot Availability: 18/11/2025

General Availability: 02/12/2025

Predecessor: 2025.2.44

Release Purpose:

• New Features and Enhancements
• Generic 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 previous production version of the sensor (2023.1.75).

Name Changes:

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

Files Updated:

• fsatp.sys
• fsatpl.exe
• fsatpn.exe
• install.exe
• sensor_control.exe

New Features and Enhancements:

• New detections and detection improvements
• Improved process protection

General Maintenance:

• Bug fixes and dependency updates

OS Support:

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

Please note that Windows 7 and Windows Server 2008 (R2) are not supported. On endpoints where these operating systems are in use, the Countercept agent will not be updated, and the previous sensor version (2024.2.31) will continue to run. New Countercept agent installations to these operating systems are now impossible.

The update is related to the Countercept Agent’s Sensor component. The Sensor component gathers data to be analyzed in the WithSecure backend to identify any malicious activity.

Product Name: Countercept Agent for Linux – Sensor Component

Version: 2025.2.185

Pilot Availability: 10/11/2025

General Availability: 17/11/2025

Predecessor: 2025.2.168

Release Purpose:

• Generic Maintenance

Customer Action Required:

• N/A

Name Changes:

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

Files Updated:

• sensor

New Features and Enhancements:

• N/A

Generic Maintenance:

• Dependency updates and bug fixes

OS Support:

• AMD64
  • AlmaLinux 8.4 – 9.x
  • Amazon Linux 2
  • CentOS 7, 8
  • Debian 10, 11, 12
  • Oracle Linux 7, 8, 9 (RHCK and UEK)
  • RHEL 7, 8, 9
  • Rocky Linux 8, 9
  • SUSE Linux Enterprise Server 12 SP3 – SP5
  • SUSE Linux Enterprise Server 15
  • Ubuntu 18.04, 20.04, 22.04, 24.04
• ARMv8/AArch64
  • Debian 11, 12
  • Rocky 9
  • Ubuntu 22.04, 24.04

Please note that CentOS 6 and RHEL 6 are not supported. The Countercept Agent will break with this update, on endpoints where these operating systems are in use. WithSecure recommends upgrading these endpoints to the supported versions of the operating system, or switching clients to managed updates in collaboration with the WithSecure Engagement team.

The update is related to the Countercept Agent’s FSBG components. The FSBG component is responsible for the core functionality (e.g. settings management and updates) of the Countercept Agent and does not affect the components responsible for telemetry collection or response.

Product Name: Countercept Agent for Linux – FSBG

Version: 1.0.923

Pilot Availability: 04/11/2025

General Availability: 11/11/2025

Predecessor: 1.0.922

Release Purpose:

• Generic Maintenance

Customer Action Required:

• N/A

Name Changes:

• Several auxiliary files have been added in this release.
• No changes to process, or service names.

Files Updated:

• Most files are updated with this release.

New Features and Enhancements:

• N/A

Generic Maintenance:

• Changes to the functionality not utilized by Countercept.
• Minor bug fixes and improvements.

OS Support:

• AMD64
  • AlmaLinux 8.4 – 9.x
  • Amazon Linux 2
  • CentOS 7, 8
  • Debian 10, 11, 12
  • Oracle Linux 7, 8, 9 (RHCK and UEK)
  • RHEL 7, 8, 9
  • Rocky Linux 8, 9
  • SUSE Linux Enterprise Server 12 SP3 – SP5
  • SUSE Linux Enterprise Server 15
  • Ubuntu 18.04, 20.04, 22.04, 24.04
• ARMv8/AArch64
  • Debian 11, 12
  • Rocky 9
  • Ubuntu 22.04, 24.04

Please note that CentOS 6 and RHEL 6 are not supported. The Countercept Agent might break with this update, on endpoints where these operating systems are in use. WithSecure recommends upgrading these endpoints to the supported operating system versions, or switching clients to managed updates in collaboration with the WithSecure Engagement team.

The update is related to the Countercept Agent’s Ultralight Core component. 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: 2.1.20934

Pilot Availability: 30/10/2025

General Availability: 06/11/2025

Predecessor: 2.1.20768

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
• FsPisces.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

This is a notification that the update to our Windows agent’s Ultralight Core planned for GA release tomorrow, 15th of October 2025, has been cancelled. A new release schedule will be communicated when we have identified and resolved the observed issues. We apologize for the delays related to this particular release, but we are committed to making sure that we release content with the highest possible quality.

The update is related to the Countercept Agent’s Security Cloud Core component. The Security Cloud Core component provides means for accessing WithSecure’s Security Cloud functionalities utilized by the agent’s detection components.

Product Name: Countercept Agent for Windows – Security Cloud Core

Version: 2.1.20854

Pilot Availability: 09/10/2025

General Availability: 16/10/2025

Predecessor: 2.1.20491

Release Purpose:

• General maintenance

Customer Action Required:

• N/A

Name Changes:

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

Files Updated:

• install.exe

New Features and Enhancements:

• N/A

General Maintenance:

• Updated the third-party curl library to the latest version.
• General maintenance of functionality not utilized by Countercept.

OS Support:

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