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Indignant, caustic comments that simply discard all presented evidence such as this is the primary reason why people with the relevant experience have reduced their contributions on HN. I suspect I'll join their ranks too.
If you joint "their ranks", you've simply gone down the bit of the "social media + expertise" bell curve, where the more expertise you get on a particular topic, the less you want to engage about it in public.
This is not unique to any one field or realm of knowledge.
Just about everything in that wall of text is wrong, but it’s rather pointless to engage someone who clearly has never reverse engineered a single thing with a modicum of defense, yet has tons of opinions on the subject. It’s like debating the pros and cons of programming languages with someone whose claim of expertise is having used computers. I totally get gp’s frustration. Denial of service with too many absurd points is real.
> If you explain what you disagree with, maybe people would learn something.
TFA explains in detail why reverse engineering is necessary, and specifically what is achieved by reverse engineering which part. ggp clearly has zero interest in learning when much of what they wrote has been refuted in the damn post being discussed. Other people can RTFA to learn as well, it’s a good technical post, and we don’t get enough of those these days.
see: https://news.ycombinator.com/item?id=43748681 and https://news.ycombinator.com/item?id=43749282
all of those can't really work if the javascript payload is easily comprehensible, because you can just write your own implementation in python or whatever.
All you've posted so far is "I don't think <other people's points>" while being wildly wrong. It's on you to explain handwaves like "just observe the calls and mimic them", but I don't think you'll do that, plus anyone with experience here can tell it's nonsense anyway, so here's where I disengage.
Edit: I'll add another point of view as someone who has implemented my own obfuscation scheme in a product where throwing up a third party CAPTCHA isn't an option (the above is from having studied and worked around other people's obfuscation schemes, including TikTok's). Obfuscation is an arms race so there's no 100% winning, but my implementation, while vastly simpler and probably won't stop LukasOgunfeitimi, reduced the observable abuse of our product down to effectively zero. Turns out most hackers are pretty dumb. So, this shit works, "I don't think" be damned.
Otherwise also known as sealioning: https://en.wikipedia.org/wiki/Sealioning
> it has opcodes that you can write to in another higher-level "language"
VMs aren't just VirtualBox.
TikTok obfuscates their frontend because they fingerprint the device and send it to their server, likely as an anti-fraud thing. Generally these kinds of things will make it so that you can't treat the frontend as a black box and replay requests or do anything simple like that. For example, if they add an incrementing counter to each request and then encrypt it, and then they see you send the same request again, then they will flag you for doing something fishy. You'd only know what they were doing if you reverse engineered the frontend. This isn't security per se but it makes people have to reverse engineer the code to mimic genuine behavior, which is their goal.
As for TikTok being a cyberweapon: you're going to have to back up that claim. Obfuscating an app and then installing it on people's phones is not as clever an idea as you think it is.
But that's basically an emulator of a VM, isn't it? It's like rewriting the Flash AVM2 into JS... it's still running in JS whereas the original VM was C++. It could JIT compile stuff but only because it literally was reserving memory that could overflow, and (semi-technical take here) from that advantage, of being closer to the metal, flowed all of the flaws in AVM2 that precipitated most of Adobe's woes with Flash. A VM implant in a web page that uses a plugin like Java or Flash, to get around running browser-sandboxed code, which can take over physical memory, is far different from just emulating a VM in Javascript. I wouldn't call writing a ton of opcodes in JS, which resolved to JS functions, a "virtual machine", because it isn't reserving anything or doing anything that Javascript can't do. Someone correct me here if I'm wrong... this is just heavy-duty obfuscation.
Also, one major purpose of a VM is to improve performance over what's available in the browser. If you use that as a measurement, this clearly doesn't fit that goal.
I think you're using a different definition of the term VM than most other people here. An "emulated VM" is a VM too.
> one major purpose of a VM is to improve performance over what's available in the browser.
That's definitely a very nonstandard interpretation. Many VMs are, intentionally, much less capable (in a permissions sense; in a computational sense, they're almost always exactly as capable) than the host environment they run in.
The article mentioned that important API calls are signed. So you would need at least partially to deconstruct their front-end to invoke the calls.
Any other nefarious purposes aside, this seems explicitly anti-bot because you can change the obfuscation whenever you like, forcing another RE effort.