1. You have to get your software installed, even though the user doesn’t want it.
2. Once your software is installed, you have to keep it from being uninstalled, even though the user wants it gone.
These are the same two technical problems that spyware designers face.
People who face the same technical problems tends to find the same technical solutions. How do you get software installed against the user’s wishes? You mislead the user about what is being installed, or about the consequences of installation. Or you install without getting permission at all. How do you keep software from being uninstalled? You don’t provide an uninstaller. Or you provide an uninstaller that doesn’t really uninstall the whole program. Or you try to cloak the software so the user doesn’t even know it’s there."