F-Secure Host Process high CPU usage

The problem is that F-Secure Host Process has a high CPU usage of around 30-35 %. After boot it is very low  for some time but will eventually get higher and stays there until I restart the computer.


The scheduled scan is disabled. I also made a full computer scan and it found nothing.


This is very annoying problem, as it makes my computer pretty sluggish. Is there a solution?


  • Simon
    Simon Posts: 2,665 Superuser
    Does this happen every time you start your machine, regardless of how long you've had it on? I was just wondering if maybe it's trying to download and install all the updates? That can occasionally take a little while, and if it's a major product update, your computer may be sluggish for a little while, depending on its usual capabilities. Do you know where to check to see if all the latest signatures are installed? If not, come back to us, and we can help with that.
  • Kestis
    Kestis Posts: 4 New Member

    The high CPU usage lasts for hours. Yesterday it lasted at least six hours.


    I made the update check and it succeeded. Is there something else I should check?

  • Simon
    Simon Posts: 2,665 Superuser
    That doesn't sound right. The other possibility is that there is a conflict with some other software on your machine. Do you have any other security software installed?
  • Kestis
    Kestis Posts: 4 New Member

    There is no other security software on my computer.


    This did not happen yesterday.  My computer was on for the entire day, but the CPU usage kept low. But today it happened again. I started my computer in the morning and left it open. Then I was away for a couple of hours and when I came back the fshoster64.exe was using about 33% of CPU.

  • Kestis
    Kestis Posts: 4 New Member

    Any help? The problem persists.

    I have monitored the process more closely for the last couple of weeks. The high CPU usage does not happen every day but most days it does happen. Also the time before the high CPU usage begins seems to be random. Sometimes it starts almost immediately after booting the computer but sometimes it takes hours to begin.

  • Simon
    Simon Posts: 2,665 Superuser

    The trouble with this is, it could be almost anything. I wonder if your best option might be to engage in a Chat support session, and see what they suggest?


    Contact Support by Phone or Chat

  • Ville
    Ville Posts: 642 F-Secure Employee



    It sounds like there is some kind of busy loop in the code in one of the plugins that are loaded to the hoster. It's really hard to say based on your description what it could be. If you can wait for the problem to happen, leave it running busy for about on hour and then, run task manager (elevated), find the process and select "Create dump file". You can then send the dump file to our support (create a ticket), who can forward it to us in R&D. With that kind of dump file we can find the thread using a lot of CPU and see what it is doing.



    (F-Secure R&D)



    F-Secure R&D, Desktop products

  • KP_
    KP_ Posts: 1 New Member

    Same issue, process% around 25-35 for several hours. Problem started this week, related to new version(s)?


    Win 10.


  • Mithon
    Mithon Posts: 1 New Member

    Same problem here, processor usage up to 50%, started yesterday. Sometimes booting the computer helps.

  • HartsaErtsi
    HartsaErtsi Posts: 2 New Member

    Same problem here, but with 60 to 75% CPU usage and constantly rising memory usage too. Now 1GB it was ower 2GB before booting. These problems start today, games are totally unplayable. Mouse start to move few seconds behind now...

  • Kym1
    Kym1 Posts: 1 New Member

    Same issue. Started after update, using all CPU resources for hours.

  • HartsaErtsi
    HartsaErtsi Posts: 2 New Member

    After few times of restarting Windows, this broblem seems to be solved for now.

  • Sarcasm83
    Sarcasm83 Posts: 3 Observer

    Same issue here aswell. Win 10... Does not happen always, but has happened about a dozen times during the last month or so, enough for me to worry about it. However, a computer reboot has always fixed this.

    For me, this always happens a few hours after booting my PC... Or more like I notice it at that point.

    I think it might just keep on hogging CPU and memory until I notice my PC working very slowly and then notice that my CPU usage is at 100%, with F-secure host process taking up most of the CPU (Currently at around 40%) and fshoster64.exe using a ton of memory (currently at 3 245 190k and steadily going up)


    Did run a virus scan and scan for updates, but problem persisted. Did create that dumpfile Ville recommended, incase I need to open a ticket about it... A very odd issue, but avoidable with a reboot for me, atleast so far..

  • TonyZi
    TonyZi Posts: 1 New Member

    Good that I am not alone with this issue.


    Just read this news: https://mspoweruser.com/microsoft-is-blocking-windows-10-april-2018-update-on-pcs-with-avast-antivirus-installed/


    Could this be the same problem with F-Secure? I have to check home which brand SSD I have on my PC.


    EDIT: I have Sandisk. So the issue has something to do with Windows10 and F-Secure update. Compatibility issue. Please fix this asap.

  • SuperJack
    SuperJack Posts: 1 New Member

    I'm having the exact same problems. Really annoying.


    Rebooting does fix it.

  • Christmas
    Christmas Posts: 3 New Member


    Capture.PNGI have the same issue as well.

    It slows my PC down significantly, swing between 17% and up towards 50% usage.

  • Christmas
    Christmas Posts: 3 New Member

    Today F-SECURE took over 60% of my CPU.
    I wonder why this has started to happen.



  • Christmas
    Christmas Posts: 3 New Member

    I uninstalled the program and released the license.
    After doing so, and reinstalled the program, there was no issues.

    Question is: Why does this even happen?

  • TifaOng
    TifaOng Posts: 32 Former F-Secure Employee

    Hi everyone,


    These are the basic steps that you can do to resolve this issue.

    1. Run a full computer scan to make sure this issue is not caused by a malware.
    2. Ensure your Windows are updated.
    3. Delete temporary files in all of your drives.
    4. Uninstall unwanted or unknown applications and conflicting security applications.
    5. Update all hardware drivers via Device Manager

    If all of the above didn't work, re-install the F-Secure program.

  • NoCtrl84
    NoCtrl84 Posts: 1 New Member

    It doesn't fix the problem for me. I've reinstalled windows 10 pro after a disc format. Problems: High cpu usage and very high memory usage (memory compression turns on).

  • TifaOng
    TifaOng Posts: 32 Former F-Secure Employee

    Hi NoCtrl84,


    Please contact our support here to further investigate the high CPU usage issue you're facing. Please collect FSDIAG in advance for ease of troubleshooting. 

This discussion has been closed.
Pricing & Product Info