If you're targeted by a 3-letter agency you can assume you're totally screwed no matter what OS you use.

If they don't have an exploit for your OS yet, they'll write one.

Also, there's an independent OS running inside your Intel CPU (vPro).

No you're not immune.

Linux kernel privilege escalation bugs come out all the time. There is a long documented history of Linux rootkits. And I'm assuming you are accessing HN through a browser: Firefox/Chrome browser exploits with sandbox escapes get reported each year. Also you probably boot using UEFI, and there was presentation last year about UEFI bootkits which can hook into Kernels.

In addition, Ubuntu is one of the most popular Linux distros (if not the most) and doesn't use rolling releases, so it's probably an easier target compared to most distros.

You can't achieve security strictly through technology choices, such as which operating system you choose. Although there is some value in choosing less-popular technology.

I certainly wouldn't rely on being "immune", but I'd take some solace in the idea that I'd be unlikely to be swept up in internet-scale exploit-all-the-things kind of programs. (If you're actually an NSA target, I doubt any device with more transistors than a flashlight should be considered "immune".)

Yes the spyware would have to be targeted to the OS they want to infect. There's no reason to believe Linux would be immune though.

I imagine using an encrypted filesystem would be immune though.

Yes:

>The supported file systems are: FAT, NTFS, EXT3 and UFS.

sits specifically targeting most Windows versions, Linux and OSX.