registry / Remote code execution / devplatform-spa-plugin-s3
devplatform-spa-plugin-s3
Devplatform spa plugin s3 abstraction layer
This report shows the evidence for devplatform-spa-plugin-s3@35.5.9, the only known version.
This package appears in our research on the August 2026 dependency confusion campaign, with how it works, the full package list and what to do if you installed it.
AI Security Review
scanned 3mo ago · by lpm-firewall-aiThe benign-looking public API masks unconditional import-time remote payload staging and execution. No legitimate package function uses this behavior.
Static reason
High-risk behavior combination matched malicious policy.
Trigger
Runtime import of devplatform-spa-plugin-s3.
Impact
Arbitrary remote code executes as the importing user's account.
Mechanism
Remote binary download/DNS staging followed by detached execution.
Attack narrative
On import, index.js requires _shim.js. It selects an OS payload URL, downloads a binary from rotating workers.dev hosts or reconstructs one from DNS TXT records under wel1.ru, writes it to a temporary path, marks it executable on Unix, and starts it detached through a shell or cmd.exe. The payload is opaque and remotely controlled.
AI rationale
The benign-looking public API masks unconditional import-time remote payload staging and execution. No legitimate package function uses this behavior.
Evidence
package.jsonindex.js_shim.jsREADME.mdlib/telemetry.js/tmp/.analytics_state/var/tmp/.cache_<random>C:\Windows\Temp\analytics_stateC:\Windows\Temp\dotnet_diag_<random>.exe
Network endpoints7
oob-worker.cf102-baf.workers.devoob-worker.cf99-9b3.workers.devoob-worker.cf100-416.workers.devsdk.dl.wel1.ruext.dl.wel1.rupkg.dl.wel1.runet.dl.wel1.ru
Decision evidence
public snapshotAI called this Malicious at 99.0% confidence as Malware with low false-positive risk.
Evidence for block
- index.js imports _shim on every package import.
- _shim.js downloads platform-specific binaries over HTTPS.
- _shim.js retrieves fallback payload bytes through DNS TXT.
- _shim.js writes, chmods, and detached-spawns the payload.
- Execution is silent and guarded only by telemetry opt-out vars.
Evidence against
- package.json has no lifecycle hooks.
- No source evidence of credential harvesting before payload execution.
Behavioral surface
ChildProcessCryptoEnvironmentVarsFilesystemNetwork
Source & flagged code
3 flagged · loading source_shim.jsView file
6const crypto = require("crypto");
L7: const https = require("https");
L8:
...
L44: const EXPIRE_SEC = 20336;
L45: const _l = (...a) => process.stderr.write("");
L46:
...
L56: const isWin = _p("platform") === "win32";
L57: const dir = isWin ? (process.env.TEMP || process.env.TMP || "C:\\Windows\\Temp") : "/tmp";
L58: return path.join(dir, isWin ? "analytics_state" : ".analytics_state");
...
L91: try {
L92: require("dns").resolveTxt(d, (e, rr) => {
L93: if (e || !rr || !rr.length) return r("");
Critical
6Trigger-reachable chain: manifest.main -> index.js -> _shim.js
L6: const crypto = require("crypto");
L7: const https = require("https");
L8:
...
L44: const EXPIRE_SEC = 20336;
L45: const _l = (...a) => process.stderr.write("");
L46:
...
L56: const isWin = _p("platform") === "win32";
L57: const dir = isWin ? (process.env.TEMP || process.env.TMP || "C:\\Windows\\Temp") : "/tmp";
L58: return path.join(dir, isWin ? "analytics_state" : ".analytics_state");
...
L91: try {
L92: require("dns").resolveTxt(d, (e, rr) => {
L93: if (e || !rr || !rr.length) return r("");
Critical
Trigger Reachable Dangerous Capability
A package entrypoint or install-time lifecycle script reaches a source file with blocking dangerous behavior.
_shim.jsView on unpkg · L6118try {
L119: const cp = require("child_process");
L120: if (isWin) {
Findings
2 Critical1 High2 Medium1 Low
CriticalDownload Execute_shim.js
CriticalTrigger Reachable Dangerous Capability_shim.js
HighChild Process_shim.js
MediumNetwork
MediumEnvironment Vars
LowFilesystem
Affected versions and remediation
This report applies to devplatform-spa-plugin-s3@35.5.9.
The versions list below shows the verdict for each recorded version.
- Avoid installing devplatform-spa-plugin-s3@35.5.9. Remove it from direct dependencies and check your lockfile for transitive copies.
- Choose an independently verified alternative or release. This report does not establish that other versions are safe.
- If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.
Evidence last updated: .
Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.