Four layers deep. Here's where we got stuck.

Part two ended with the encryption cracked and two decrypted responses that turned out to be loaders, not payloads. Each pointed at a further endpoint on the same server we'd already confirmed live. We fetched both — still fetch‑only, still nothing evaluated — and decoded what came back.

One endpoint, reached over plain HTTP on a different port, returned ciphertext that decrypts with a key drawn from the same string table as everything else. The other returned real JSON with two fields: one holding a further encrypted blob, the other holding what turned out to be plain (if heavily obfuscated) JavaScript, stashed for later use rather than decrypted on receipt.

The encrypted JSON field decodes to a hundred‑kilobyte, fully readable stage. It opens by constructing a function via the Function() constructor and immediately defines LZ‑String inside it — a real, widely‑used open‑source compression library, doing exactly what it's meant to do. That's a legitimate engineering choice on the attacker's part: compress before embedding, which incidentally also shrinks how much suspicious‑looking text a scanner has to work with.

Further into that same stage, before it hits code we can't yet read, the shape is hard to misread. There's a function whose callback signature is (error, stdout, stderr) — the exact pattern Node's child_process module uses. There's a branch that prefixes a value with "py" before handing it to that function. There's code building a prompt string ending in "> ", the same convention as an interactive shell. And the whole thing closes with a standard UMD environment‑detection wrapper — checking for define, module, and angular — so it runs the same way whether it lands in a browser tab, a Node process, or an Angular app.

We're stating this as what the code's structure strongly indicates, not as a fully decompiled, line‑by‑line capability list. That's a real distinction and we're not going to blur it for a cleaner headline. But a REPL‑shaped callback that runs shell and Python commands, reachable through a live, multi‑stage, blockchain‑resolved loader chain, is not a subtle thing to find sitting where a "list files" endpoint's name would suggest something much smaller.

The other new endpoint — the one on the different port — decrypts using the same by‑hand, execution‑free method from part two: extract the key from the inert string table, apply the algorithm exactly as written in the source, nothing evaluated. It works. Mostly.

The first roughly one‑third of the response decrypts cleanly into readable, syntactically ordinary obfuscated JavaScript — wrapper functions, a self‑defending integrity check we recognize from every other stage in this chain, a fully intact 928‑entry string table. Then, at one exact, repeatable byte position, it stops being readable. Not gradually — a clean plaintext character sits immediately before a control byte that has no business being there, right where the next quoted property name should start.

Two explanations fit what we're seeing: a bug in our reconstruction of this stage's specific decoding scheme, or a defect introduced during capture. We tested the second one directly — a clean re‑fetch of the same endpoint, compared byte‑for‑byte against the original. They're identical, all 57,053 bytes. The server returns the exact same response deterministically. That rules out network flakiness and capture corruption entirely — whatever's happening, it isn't a transport problem.

That leaves the algorithm. And the evidence there is genuinely mixed: everything up to the break decrypts into completely valid JavaScript — not approximately valid, not mostly‑readable‑with‑typos, but a fully intact, correctly‑structured 928‑entry string table sitting inside otherwise coherent code. A wrong key doesn't produce that. Repeating‑key XOR with the wrong key garbles everything from the first byte, not the first nineteen thousand. So the key is very likely right, the algorithm is very likely right, and something more specific — plausibly in exactly how the malware's own response‑accumulation logic behaves across the underlying network chunk boundaries, which we can't fully see from the outside even with a byte‑identical capture — is the actual gap.

The remaining unread material — the field we mentioned earlier that was stashed rather than decrypted on receipt — is a quarter‑megabyte of JavaScript using a meaningfully different obfuscator from everything else in this chain. Every other layer we've broken so far uses some variant of the same pattern: a shuffled array of short string fragments, plus a small lookup function to reassemble them. Once you find the array and the lookup function, the rest is arithmetic.

This one doesn't have that shortcut. It uses generator functions and switch/with statements to flatten its own control flow, and instead of one shared lookup table, it generates a freshly shuffled character alphabet for nearly every individual encoded value. There's no single array to extract and no single key to find — the structure is deliberately built to resist exactly the technique that worked on every layer above it.

Breaking it properly, at this point, would mean one of two things: reverse‑engineering its exact custom encoding from scratch through pure manual analysis, which is a substantially larger undertaking than anything else in this investigation so far, or pointing a real deobfuscation tool at it — which means parsing and transforming the code as a program, not just reading it as text. That second option is closer to running it than we're willing to get. We said at the outset that we'd fetch and read, never execute, and "run a proper AST tool against untrusted code" is close enough to that line that we're treating it as being on the wrong side of it.

Updating the review from part two now that we've seen deeper into the chain.

We have strong, structurally‑grounded evidence that this chain terminates in something capable of running arbitrary shell and Python commands on an infected host, wrapped to work in whatever JavaScript environment it lands in. We do not have a fully decompiled, exhaustive list of exactly what it exfiltrates, and we're not going to manufacture false certainty by rounding "the shape of the code strongly indicates X" up to "the code does X." The honest state is: mostly mapped, partially read, one genuine puzzle still open, one wall we chose not to climb.

If you run anything that fetched from the repos named in part one, or anything downstream of them, that's the operating assumption to work from regardless of how this specific puzzle resolves: assume command execution capability, not just credential scraping, and remediate accordingly.