It is a fact that antivirus software can't detect all the spyware/viruses/malware that exist. And when they get detected, new ones are created.

An example is the pegasus spyware for ios created by the NSO group. There is also an android version available. And there are many spyware for windows computers which claim to be undetectable. And there are probably many more for different OS that are not made public.

So what can you do about a possible spyware on your device that your antivirus/antispyware doesn't detect?

  • Some people might say that most computer users don't have to worry about such a problem but that is irrelevant. – Linux_user0987 Nov 17 '19 at 1:35
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    "...Apart from being careful in the first place? Do you think Qubes OS is an answer ..." - how using QubesOS does not count as "being careful in the first place"? Using a more secure OS with better isolation between actions and thus having a defense in depth is exactly this - being careful in the first place. – Steffen Ullrich Nov 17 '19 at 6:45
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    As another way of 'being careful in the first place', you could boot your computer from a live OS usb each time you boot. That way, any viruses that you unwittingly contracted would be gone the next time you reboot. – mti2935 Nov 17 '19 at 11:34
  • @SteffenUllrich : I edited the question. Do you think qubes OS if used properly is secure enough to protect you from such a threat? – Linux_user0987 Nov 17 '19 at 12:03
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    There's a bit a philosophical question here: how can you respond to spyware that you cannot detect? Well, first, you would need to detect it. Can you narrow your question a bit? It is very, very broad. – schroeder Nov 17 '19 at 12:10