What is k9filter.exe?

The genuine k9filter.exe file is a software component of Blue Coat by Blue Coat Systems.
Blue Coat Systems Inc., originally known as CacheFlow is based in Sunnyvale, California, United States. It has been under operations since 1996 and provides web security and networking solutions. Over the years, Blue Coat has run into some criticism and controversy, especially over the usage of their products by the Syrian government to block internet access to people. K9 Web Protection is a free filter for the Internet which includes parental control software for personal computer. It features ways to block certain harmful websites ranging through 70 categories, including pornography, drugs, gambling, malware, spyware and phishing.

K9Filter stands for K9 Web Protection Filter

The .exe extension on a filename indicates an executable file. Executable files may, in some cases, harm your computer. Therefore, please read below to decide for yourself whether the k9filter.exe on your computer is a Trojan that you should remove, or whether it is a file belonging to the Windows operating system or to a trusted application.

Click to Run a Free Scan for k9filter.exe related errors

K9filter.exe file information

Windows Task Manager with k9filter
K9filter.exe process in Windows Task Manager

The process known as K9 Web Protection Filter or Blue Coat (version K9 Web Protection) belongs to software Blue Coat (version K9 Web Protection, K9 Web Protection) or K9 Web Protection or Blue Coat?K9 Web Protection by Blue Coat Systems (

Description: K9filter.exe is not essential for Windows and will often cause problems. The k9filter.exe file is located in a subfolder of "C:\Program Files". Known file sizes on Windows 10/8/7/XP are 184,320 bytes (53% of all occurrences), 1,078,560 bytes and 8 more variants. 
The program is not visible. The file is not a Windows system file. There is no description of the program. The application listens for or sends data on open ports to a LAN or the Internet. K9filter.exe is able to monitor applications. Therefore the technical security rating is 55% dangerous, however you should also read the user reviews.

Uninstalling this variant: If you have any problems with k9filter.exe, you can also uninstall the program using the Control Panel ⇒ Uninstall a ProgramBlue Coat K9 Web Protection or Blue Coat® K9 Web Protection or contact to assist you.

Recommended: Identify k9filter.exe related errors

Important: Some malware camouflages itself as k9filter.exe, particularly when located in the C:\Windows or C:\Windows\System32 folder. Therefore, you should check the k9filter.exe process on your PC to see if it is a threat. We recommend Security Task Manager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PC World.


User Comments

Web Filter by Blue Coat Systems
  Rick Ahlander   (further information)
Web Filter and not a shabby one at that
  Pheonix   (further information)
Is a protection filter
  Francisco Viturro   (further information)
its a web filtering program
It blocks unwanted sites
Blue Coat K9 Web Protection
  Barry Zeeko  

Rating chart

Summary: Average user rating of k9filter.exe: based on 8 votes with 6 user comments. 4 users think k9filter.exe is essential for Windows or an installed application. One user thinks it's probably harmless. One user thinks it's neither essential nor dangerous. One user suspects danger. One user thinks k9filter.exe is dangerous and recommends removing it.

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Best practices for resolving k9filter issues

A clean and tidy computer is the key requirement for avoiding problems with k9filter. This means running a scan for malware, cleaning your hard drive using cleanmgr and sfc /scannow, uninstalling programs that you no longer need, checking for Autostart programs (using msconfig) and enabling Windows' Automatic Update. Always remember to perform periodic backups, or at least to set restore points.

Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or, for Windows 8 and later versions, executing the DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

To help you analyze the k9filter.exe process on your computer, the following programs have proven to be helpful: Security Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. Malwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.

Other processes

k9filter.exe [all]