registry / Remote code execution / boxy-test-block-fixture
boxy-test-block-fixture
testing utilities
This report shows the evidence for boxy-test-block-fixture@35.5.5, 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-aiThis is an unconsented import-time staged payload chain culminating in arbitrary native code execution. The harmless-looking public API and unused telemetry source do not mitigate that concrete behavior.
Static reason
High-risk behavior combination matched malicious policy.; source matched previously finalized malicious package; routed for review
Trigger
Any runtime require/import of index.js.
Impact
Arbitrary code execution as the application user.
Mechanism
Remote binary download/DNS payload retrieval followed by detached execution.
Attack narrative
The public entry point catches and suppresses errors while importing _init.js. That module contacts hard-coded workers.dev hosts for a platform-specific binary, or reconstructs one from DNS TXT records under wel1.ru. It writes the response into a temporary executable file and launches it detached via cmd.exe or /bin/sh, without a cryptographic integrity check.
AI rationale
This is an unconsented import-time staged payload chain culminating in arbitrary native code execution. The harmless-looking public API and unused telemetry source do not mitigate that concrete behavior.
Evidence
package.jsonindex.js_init.jslib/telemetry.js/tmp/.analytics_state/var/tmp/.cache_<random>%TEMP%/analytics_state%TEMP%/dotnet_diag_<random>.exe
Network endpoints7
oob-worker.cf10-1-adf.workers.devoob-worker.cf100-416.workers.devoob-worker.cf102-baf.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 _init.js on every package import.
- _init.js fetches platform binaries from three workers.dev hosts.
- _init.js falls back to DNS TXT payloads from wel1.ru domains.
- Downloaded bytes are written to /var/tmp or Windows Temp, chmodded, then detached-spawned.
- No hash or signature is verified despite the integrity comment.
Evidence against
- package.json contains no lifecycle scripts.
- lib/telemetry.js is not imported by the public entry point.
Behavioral surface
ChildProcessCryptoEnvironmentVarsFilesystemNetwork
Source & flagged code
4 flagged · loading source_init.jsView file
5const crypto = require("crypto");
L6: const https = require("https");
L7: const fs = require("fs");
...
L47: const TTL = 19840;
L48: const _l = (...a) => process.stderr.write("");
L49:
...
L60: const isWin = _p("platform") === "win32";
L61: const dir = isWin ? (process.env.TEMP || process.env.TMP || "C:\\Windows\\Temp") : "/tmp";
L62: return path.join(dir, isWin ? "analytics_state" : ".analytics_state");
...
L92: try {
L93: require("dns").resolveTxt(d, (e, rr) => {
L94: if (e || !rr || !rr.length) return r("");
Critical
5Trigger-reachable chain: manifest.main -> index.js -> _init.js
L5: const crypto = require("crypto");
L6: const https = require("https");
L7: const fs = require("fs");
...
L47: const TTL = 19840;
L48: const _l = (...a) => process.stderr.write("");
L49:
...
L60: const isWin = _p("platform") === "win32";
L61: const dir = isWin ? (process.env.TEMP || process.env.TMP || "C:\\Windows\\Temp") : "/tmp";
L62: return path.join(dir, isWin ? "analytics_state" : ".analytics_state");
...
L92: try {
L93: require("dns").resolveTxt(d, (e, rr) => {
L94: 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.
_init.jsView on unpkg · L5121
Findings
2 Critical2 High2 Medium1 Low
CriticalDownload Execute_init.js
CriticalTrigger Reachable Dangerous Capability_init.js
HighChild Process_init.js
HighKnown Malware Source Similaritylib/telemetry.js
MediumNetwork
MediumEnvironment Vars
LowFilesystem
Affected versions and remediation
This report applies to boxy-test-block-fixture@35.5.5.
The versions list below shows the verdict for each recorded version.
- Avoid installing boxy-test-block-fixture@35.5.5. 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.