It may be superfluous to point this out but this seems to be talking about malicious uses of narrow AI, rather than malicious strong AI. The only defense against a malicious strong AI is, of course, a friendly strong AI.
A bomb that is 1,000 times for powerful than a nuclear weapon. Again, currently science fiction. Can't say anything about that either?
The fact that it doesn't exist right now doesn't mean we can't say anything about it, and the fact that it's potentially dangerous means we should be trying, at least, to think about it. Assuming it really is as dangerous as some people claim, do you really want to wait around until it's no longer science fiction, and only then, after it's too late, start thinking about it?
Yes. It's not the fact that it doesn't exist, it's the fact that not only is it not clear that it's even physically possible, anything you come up with can just be handwaved away by this mystical property known as "intelligence". Your two examples don't have this problem so they're not similar.
Most of the literature I've seen about AGI is about theories on how to build it, or theories on how to build it safely (e.g. so it has stable preferences that align with human values). Not stuff on "how to defend yourself against a rogue AGI", because there really is nothing you can say about that.
Well, actually no. It's possible to say one thing (and as far as I'm aware, only this thing): You'd better have an even smarter friendly AI on your side, or you're almost certainly boned.
Are you sure? Was the world better off with both the US and Russia having nukes? Perhaps, or perhaps we got incredibly lucky that we didn't destroy ourselves. It is quite possible that a world where we have a single malicious AI is better than a world where a malicious AI and a friendly AI are locked in a battle to the death.
Strong AI is not hard to reason about because it is science fiction. As edanm pointed out, it is entirely possible to reason about science fiction. The difference is that the examples edanm points out are extensions or modifications of things that do exist and that provides a basis from which we can reasonably extrapolate.
We can't reason about strong AI precisely because we don't have as good of an existing example from which we can extrapolate. The best we have is the human mind. The extrapolation from the human mind is precisely the basis for argument that "friendly strong AI" is the best/only response to to "malicious strong AI" since the thing that keeps malicious humans in check is "good" humans.
We don't even know if or to what degree 'super-intelligence' is possible. For all we know, there may be fundamental trade offs between the different skills necessary for general intelligence that may provide functional limits to the degree to which intelligence can be super human.
It's actually human minds. Organizations of humans like major corporations and government possess the sort of resources that we imagine a super AI would have.
While this is true, it would be extremely surprising if evolution's first stab at higher intelligence (humans) came anywhere near the theoretical limits of what intelligence could be if directly selected for.
Just remove the size and energy consumption constraints imposed on the human brain by what the human body can support, and you should be able to get a significant improvement without changing the base architecture much at all.
Digitize and allow for copy/paste of "brains", and now you've got 30,000,000 copies of Einstein working together on problems but each specializing in their own pursuits, each of which doesn't get tired and lives forever, and can open very high-throughput direct neural communication channels with the other Einsteins whenever they need to share knowledge.
Start tweaking the virtual brain's "chemical" environment, and you can probably supercharge them by doing all sorts of stuff that would kill a real human but is fine when all you care about is making a simulated brain work better (virtual megadoses of Ritalin, massive tweaks to neurotransmitter behaviors, etc.).
These are just a few obvious ideas, but it's hard to imagine that together they couldn't scale intelligence up at least past the point where we could ever hope to keep up, as long as we got it into digital form in the first place. You're correct that there will be an architectural "wall" somewhere, but chances are that human intelligence is more in the "vacuum tubes and punch cards" regime than the "Moore's law is done" one. Whatever is there when that wall is hit would be so far beyond us that it might as well be called super-intelligent, even if it can't improve further.
Of course there's at least a couple things you can say. "You should have built a friendly one first", or "convince it you're harmless". Or more grimly, "become harmless".
Life is propagated through sexual reproduction.
There is also no "infection".
The joke, as told properly, is: "What is spread through sex, 100% fatal and literally everyone you know has had it?"
If the hypothetical malicious AI gets built, your JDAMs will be about as advanced by comparison as a pointy stick against an M-16.
Is somebody going to take a JDAM to Google's data center in Atlanta or Amazon's data center in Seattle? Blow up Facebook in Palo Alto? Won't the US Air Force have a problem with that?
Entertaining perhaps, but ultimately pointless and silly.
For a counterpoint (and not even a particularly malicious strong AI), see The Adolescence of P1.