Eli5: How do unwanted programs prevent themselves from being uninstalled?

Question

Eli5: How do unwanted programs prevent themselves from being uninstalled?

In: 8

Answer 1

I can think of a couple ways. Achieving a higher control level over the system (as in, gaining admin/root/kernel privileges). Or trickery like copying itself in many locations to evade detection and keep running unnoticed. Even linking itself to the boot process in such a way the OS doesn’t even know it’s there.