Bash. By default it might seem less featureful than zsh… but bash is a lot more powerful and extensible than some give it credit for. It might be more complex to set it up the way you like it, but once you do it, that configuration can be ported over wherever bash exists (ie. almost everywhere).

It can be formatted “nicely” with no issue. But that doesn’t necessarily make it easy to understand.

What that person posted was in a function named smb() that only gets called by rmb() under certain conditions, and rmb() gets called by AdB() under other conditions after being called from eeB() used in BaP()… it’s a long list of hard to read minified functions and variables in a mess of chained calls, declared in an order that doesn’t necessarily match up with what you’d expect would be the flow.

In the same file you can also easily find references to the user agent being read at multiple points, sometimes storing it in variables with equally esoteric short names that might sneak past the reader if they aren’t pedantic enough.

Like, for example, there’s this function:

function vc() {
    var a = za.navigator;
    return a && (a = a.userAgent) ? a : ""
}

Searching for vc() gives you 56 instances in that file, often compared to some strings to check what browser the user is using. And that’s just one of the methods where the userAgent is obtained, there’s also a yc=Yba?Yba.userAgentData||null:null; later on too… and several direct uses of both userAgent and userAgentData.

And I’m not saying that the particular instance that was pointed out was the cause of the problem… it’s entirely possible that the issue is somewhere else… but my point is that you cannot point to a snippet of “nicely formated” messed up transpiler output without really understanding fully when does it get called and expect to draw accurate conclusions from it.

It doesn’t really matter whether it was “targeted” at Firefox specifically or not, what matters is whether the website has logic that discriminates against Firefox users. Those are 2 different things. “End” vs “means”.

I wouldn’t be surprised if the logic was written by some AI, without specifically targeting any browser, and from the training data the AI concluded that there’s a high enough chance of adblocking to deserve handicapping the UX when the browser happens to be Firefox’s. Given that all it’s doing is slowing the website down (instead of straight out blocking them) it might be that this is just a lower level of protection they added for cases where there’s some indicators even if there’s not a 100% confidence an adblock is used.

That’s out of context. That snippet of code existing is not sufficient to understand when does that part of the code gets actually executed, right?

For all we know, that might have been taken from a piece of logic like this that adds the delay only for specific cases:

if ( complex_obfuscated_logic_to_discriminate_users ) {

    setTimeout(function() {
        c();
        a.resolve(1)
    }, 5E3);

} else {

    c();
    a.resolve(1)

}

It’s possible that complex_obfuscated_logic_to_discriminate_users has some logic that changes based on user agent.

And I expect it’s likely more complex than just one if-else. I haven’t had the time to check it myself, but there’s probably a mess of extremely hard to read obfuscated code as result of some compilation steps purposefully designed to make it very hard to properly understand when are some paths actually being executed, as a way to make tampering more difficult.