How to prevent an app from being killed in windows task manager?

Question

I want to make a repeated question. how to prevent that someone stop an application with the task manager.

I now that is posible, if you try to kill avastui.exe form the task manager the task manager say "the operation could not be completed acces denied" and it happens when de service of avast is on, when you stop the service of avast you can kill the process avastui.exe.

Someone have any idea how avast do it? how can i make it on c# or python?

Thanks in advance

Answer 1

I think it may be because things like anti-virus software are hooked into kernel-mode as drivers and can intercept user-mode input and intervene. The anti-virus may be hooked into the kernel APIs for process management, and reject calls through the process APIs to kill a process with the same PID as itself.

If this is the case, then the answer would be that no you can't as I highly doubt that C# can be run in kernel-mode.