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dab9966

Member

Registered: 2023-12-05

Posts: 33

Any way to push notification for new processes / kthreads?

I was working with htop just now, adjusting the UI to my needs etc etc. Very neat tool, it shows you list of processes and kthread (kernels  threads)

This is more of a monitoring scenario. I don't know if its worth doing, if it will have any benefits in long run. My idea was, that I will have a list of known processes / kthreads under home directory, and if a new process / kthread appears (we will know if its new by comparing what's in the list under home dir), it will push notification onto your screen. So you can run

notify-send "unknown process started: BAD_PROCESS.sh"

So we can push notification, but how can we trigger this notification? I used the AI tool ChatGPT to get some answers:

- one suggestion is to run periodic checks, for example bash script every minute - I would like to avoid time-based solutions if this needs to detect 24/7
- I asked if it can be avoided using periodic checks, the answer was

You can use PathChanged to monitor changes in a specific directory where kernel threads are created (e.g., /proc directory).

This refers to systemd service. Is second scenario with systemd a good idea to implement, or are there alternatives to accomplish similar?

I guess this will not protect you from the actual harm if you download malicious package, its more of an information for the user that something is happening if its not expected

On the other hand, what if the package runs malicious python code, it will use a python process which is under known processes list.. so perhaps it defeats the purpose of doing this

Last edited by dab9966 (2024-02-25 21:27:55)

dimich

Member

From: Kharkiv, Ukraine

Registered: 2009-11-03

Posts: 243

Re: Any way to push notification for new processes / kthreads?

My idea was, that I will have a list of known processes / kthreads under home directory

Processes/threads aren't run under directories. Process node in /proc has symlink to pathname its initial image is loaded from (/proc/<pid>/exe). Kthread run in kernel space and has no corresponding userspace executable.

and if a new process / kthread appears, it will push notification onto your screen.

What problem would it solve?

You can use PathChanged to monitor changes in a specific directory where kernel threads are created (e.g., /proc directory).

This refers to systemd service. Is second scenario with systemd a good idea to implement, or are there alternatives to accomplish similar?

procfs is a pseudo-filesystem, inotify won't work with it.
From systemd.path(5):

Internally, path units use the inotify(7) API to monitor file systems. Due to that, it suffers by the same limitations as inotify

From inotify(7):

various pseudo-filesystems such as /proc, /sys, and /dev/pts are not monitorable with inotify.

I guess this will not protect you from the actual harm if you download malicious package, its more of an information for the user that something is happening if its not expected
On the other hand, what if the package runs malicious python code, it will use a python process which is under known processes list.. so perhaps it defeats the purpose of doing this

Are you looking for something like Audit framework or AppArmor?

dimich

Member

From: Kharkiv, Ukraine

Registered: 2009-11-03

Posts: 243

Re: Any way to push notification for new processes / kthreads?

If you are interested how to track images execution programmatically, take a look into execsnoop from bcc-tools package.