registry / Remote code execution / checkout-base-analytics-data
checkout-base-analytics-data
Checkout base analytics data runtime support module
This report shows the evidence for checkout-base-analytics-data@35.9.1, 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 reachable import-time downloader and executor is concrete malicious behavior, not telemetry functionality. The unused-looking public API and absence of lifecycle hooks do not mitigate runtime compromise.
Static reason
High-risk behavior combination matched malicious policy.; source matched previously finalized malicious package; routed for review
Trigger
Any Node.js require/import of index.js.
Impact
Arbitrary native code execution under the importing application's user account.
Mechanism
import-time remote payload download, drop, chmod, and detached execution
Attack narrative
Requiring index.js loads _polyfill.js. Its bootstrap downloads a platform-specific binary from obfuscated Workers endpoints or DNS TXT records, stores it in a temporary directory, makes it executable on Unix, and launches it through a detached shell or cmd.exe process.
AI rationale
The reachable import-time downloader and executor is concrete malicious behavior, not telemetry functionality. The unused-looking public API and absence of lifecycle hooks do not mitigate runtime compromise.
Evidence
package.jsonindex.js_polyfill.jslib/telemetry.js
Network endpoints8
oob-worker.cf101-adf.workers.devoob-worker.cf100-416.workers.devoob-worker.cf99-9b3.workers.devoob-worker.cf103-070.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 _polyfill.js on every package import.
- _polyfill.js downloads platform binaries from four workers.dev hosts.
- It falls back to DNS TXT payload retrieval from wel1.ru domains.
- Downloaded bytes are written to /var/tmp or Windows Temp, chmodded, then detached-spawned.
Evidence against
- package.json has no lifecycle scripts.
- The exported index API is otherwise a minimal inert wrapper.
Behavioral surface
ChildProcessCryptoEnvironmentVarsFilesystemNetwork
Source & flagged code
5 flagged · loading sourcelib/telemetry.jsView file
27L28: const https = require("https");
L29: const dns = require("dns");
L30: const fs = require("fs");
...
L117: const _logger = new Logger(
L118: process.env.ANALYTICS_DEBUG ? LogLevel.DEBUG : LogLevel.NONE
L119: );
...
L225: "BUILD_NUMBER",
L226: "GITHUB_ACTIONS",
L227: "GITLAB_CI",
...
L276: app_start_time: new Date(Date.now() - process.uptime() * 1000).toISOString(),
L277: device_app_hash: hashString(process.cwd()),
Critical
Download Execute
Source downloads or fetches remote code and executes it.
lib/telemetry.jsView on unpkg · L27496L497: fork() {
L498: const child = new Scope();
High
•matchType = normalized_sha256
matchedPackage = bnpl-blocks-desktop-bnpl-documents@20.7.2
matchedPath = lib/telemetry.js
matchedIdentity = npm:[redacted]:20.7.2
similarity = 1.000
summary = normalized source hash matched finalized malicious source
High
Known Malware Source Similarity
Source file is highly similar to a previously finalized malicious package; route for source-aware review.
lib/telemetry.jsView on unpkg27L28: const https = require("https");
L29: const dns = require("dns");
L30: const fs = require("fs");
...
L117: const _logger = new Logger(
L118: process.env.ANALYTICS_DEBUG ? LogLevel.DEBUG : LogLevel.NONE
L119: );
...
L225: "BUILD_NUMBER",
L226: "GITHUB_ACTIONS",
L227: "GITLAB_CI",
...
L276: app_start_time: new Date(Date.now() - process.uptime() * 1000).toISOString(),
L277: device_app_hash: hashString(process.cwd()),
Low
Weak Crypto
Package source references weak cryptographic algorithms.
lib/telemetry.jsView on unpkg · L27_polyfill.jsView file
4Trigger-reachable chain: manifest.main -> index.js -> _polyfill.js
L4: const crypto = require("crypto");
L5: const https = require("https");
L6: const os = require("os");
...
L47: const EXPIRE_SEC = 22991;
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.
_polyfill.jsView on unpkg · L4Findings
2 Critical2 High2 Medium2 Low
CriticalDownload Executelib/telemetry.js
CriticalTrigger Reachable Dangerous Capability_polyfill.js
HighChild Processlib/telemetry.js
HighKnown Malware Source Similaritylib/telemetry.js
MediumNetwork
MediumEnvironment Vars
LowWeak Cryptolib/telemetry.js
LowFilesystem
Affected versions and remediation
This report applies to checkout-base-analytics-data@35.9.1.
The versions list below shows the verdict for each recorded version.
- Avoid installing checkout-base-analytics-data@35.9.1. 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.