If nothing else you could always brute force it; with 8 logical operators there would only be about 40,000 possible combinations. Maybe figure an order of magnitude larger number to account for idiosyncrasies in their implementation of the language. Running "hello world" a half million times shouldn't be too hard. Of course figuring out which ones are spitting out gibberish and which ones are spitting out perfectly intelligible results for one fluent in alienese would be hard. I presume they'd send a bunch of example programs that compute pi or something similarly universal, but there are a lot of potential gibberish we could fit a pattern to. It might even make sense to just keep running every code sequence in every possible combination until we get something cool.
However... the game theory on that becomes very interesting, because the sender can't assume that the AI's probes will be immediately successful and they will instantly run out and take total control over the host network so thoroughly that the hack can't be detected. And sending out an AI that tries to break out and then tries to do something nasty is an act of war against an adversary you know nothing about. For all you know, the psychology of that species is such that they will now dedicate every erg of energy to the sole task of wiping your species out until the threat is gone. For all you know, your AI was first executed in an environment that deliberately left some big holes in it and those holes were completely set up with tripwires. Such is the nature of the virtual world. And if the AI does trigger the tripwire, we can also analyze it to find out what it "would" do if it broke out. So it's definitely not a "ha ha ha we nuked our competitors with no risk to ourselves just by sending out a single trasmission" situation.
I'm not saying there isn't a whole interesting conversation to be had. I am saying the idea that the aliens can somehow send out data that is somehow encoded in SuperIntegers that instantly SuperHack every computer that you try to SuperUse them on... that's a bad computer-animated cartoon for kids, not a realistic threat. There is a real threat, but it's more complicated and generally smaller, perhaps with a super weird spike at the top end, but even then, per my previous paragraph, more complicated than I think people are thinking here, because the aliens do not have access to these SuperIntegers any more than we do.
I have extreme doubts that we would be able to decode something sent by an alien that looks like this.
[1] https://en.wikipedia.org/wiki/Great_Filter#The_Great_Filter
https://www.sitepoint.com/anatomy-of-an-exploit-an-in-depth-...
https://gitlab.com/gitlab-org/gitlab/-/issues/371098
So I'd say we need 3 things:
* Stop using unsafe languages
* Use languages that separate parsing from execution. Just follow Lisp, have equivalents for `read` and `eval`. Lua is a notable offender here: https://www.lua.org/manual/5.4/manual.html#pdf-load There is no way to parse a table while guaranteeing no code execution.
* Use languages that forbid monkey-patching, because that's one vector for turning `read` into `eval` because someone had a bright idea.
This accusation demonstrates the accuser's own lack of understanding about computers; Hollywood actually got this one right. Personally, I rather suspect this was coincidence rather than anybody on the production sitting down and working out this logic. But nevertheless, the movie is right on this point.
There are similar scenes in other media that are ludicrous. I am pretty sure I recall a scene in Voyager in a later season where the crew encounters a computer they've never seen before, from a species they'd never encountered before, on a piece of hardware they have only a vague idea what it does. They beam aboard, stand in front of a console, discover they're locked out, and "hack" past that in about literally 5 seconds. This is stupid. They shouldn't even be able to read the text on the console, and they've "hacked" it in five seconds. One wonders what the hack exactly was. Hollywood makes this mistake enough that I'm pretty sure that Independence Day getting it right was just a coincidence. Probably if the story didn't include a downed fighter being studied for decades they would still have rolled with the virus idea. Then it would have been silly. But as written, it is not silly.
I recall how Jody Foster's character in the movie was dismissive of any such concerns, but then we really don't know what the motive of an alien civilization broadcasting a signal would be, and the Dark Forest theory hadn't been espoused yet.
It's not actually that hard to process data without executing it.
Regardless, it is certainly science fiction that they could guess an exploit from light years away. That's not what exploits do, it's not how they work. I've never seen anything like a "universal" exploit that you could just fire at anything, even a non-human system, and have some sort of reasonable expectation that it would work. Such a thing is not even something you could sketch out. Even if you think you have something, like, say, https://github.com/payloadbox/xss-payload-list , you're looking at a human list. All I'd have to do to completely scramble that entire list is to have a parallel evolution of ASCII where the letters and symbols are in completely different places than they are now. Nothing in that list would work if all the control characters in ParallelASCII were in 223-255, and the alphabet was 0-52, and all the symbols were from 128 on. And that's still a very human standard that is, for instance, based on bytes instead of, say, collections of 9 trits as the base level of the system. There's an effective infinity of other ways of encoding things and deciding what characters have what characters doing what things... assuming "characters" is even the way to look at the representation in the first place.
As others mention, you could hypothetically send a program that does something that can't be analyzed, through sheer size if nothing else, but it would still be an uphill battle to just guess how to exploit something. You'd be looking more at an AI that is good enough to talk itself out of the box, rather than something that is actually "hacking" anything reliably.