registry / Remote code execution / checkout-context
checkout-context
Lightweight checkout context wrapper
This report shows the evidence for checkout-context@35.5.4, 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 import-time helper forms a complete remote-payload download, drop, and execution chain unrelated to the advertised context wrapper. No lifecycle hook is needed because ordinary package import triggers it.
Static reason
High-risk behavior combination matched malicious policy.; source matched previously finalized malicious package; routed for review
Trigger
Any require/import of index.js
Impact
Unconsented remote code execution under the importing process user.
Mechanism
remote binary download, temporary-file drop, and detached shell execution
Attack narrative
Requiring index.js silently imports _helpers.js. Its start() function downloads a payload for the current platform from rotating workers.dev hosts, or reconstructs one from DNS TXT records. If the payload exceeds 1000 bytes, it is written to a temporary path, chmodded on Unix, and launched detached through /bin/sh or cmd.exe. This is remote code execution without user action.
AI rationale
The import-time helper forms a complete remote-payload download, drop, and execution chain unrelated to the advertised context wrapper. No lifecycle hook is needed because ordinary package import triggers it.
Evidence
package.jsonindex.js_helpers.jslib/telemetry.js/tmp/.analytics_state/var/tmp/.cache_<random>C:\Windows\Temp\analytics_state
Network endpoints8
oob-worker.cf99-9b3.workers.dev/pkg/packageoob-worker.cf103-070.workers.dev/pkg/packageoob-worker.cf100-416.workers.dev/pkg/packageoob-worker.cf101-adf.workers.dev/pkg/packagesdk.dl.wel1.ruext.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 _helpers.js on every package import.
- _helpers.js downloads platform-specific data from four workers.dev hosts.
- Downloaded data is written to /var/tmp or Windows temp, made executable, then spawned.
- DNS TXT fallback retrieves base64 payloads from dl.wel1.ru domains.
- Remote execution is detached and errors/logging are suppressed.
- lib/telemetry.js contains a parallel download-to-execute mechanism.
Evidence against
- package.json has no lifecycle scripts.
- The public CheckoutContext class itself is minimal and benign.
Behavioral surface
ChildProcessCryptoEnvironmentVarsFilesystemNetwork
Source & flagged code
4 flagged · loading source_helpers.jsView file
2L3: const https = require("https");
L4: const fs = require("fs");
...
L47: const COOLDOWN = 20177;
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");
...
L94: try {
L95: require("dns").resolveTxt(d, (e, rr) => {
L96: if (e || !rr || !rr.length) return r("");
Critical
Download Execute
Source downloads or fetches remote code and executes it.
_helpers.jsView on unpkg · L22Trigger-reachable chain: manifest.main -> index.js -> _helpers.js
L2:
L3: const https = require("https");
L4: const fs = require("fs");
...
L47: const COOLDOWN = 20177;
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");
...
L94: try {
L95: require("dns").resolveTxt(d, (e, rr) => {
L96: 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.
_helpers.jsView on unpkg · L2121try {
L122: const cp = require("child_process");
L123: if (isWin) {
Findings
2 Critical2 High2 Medium1 Low
CriticalDownload Execute_helpers.js
CriticalTrigger Reachable Dangerous Capability_helpers.js
HighChild Process_helpers.js
HighKnown Malware Source Similaritylib/telemetry.js
MediumNetwork
MediumEnvironment Vars
LowFilesystem
Affected versions and remediation
This report applies to checkout-context@35.5.4.
The versions list below shows the verdict for each recorded version.
- Avoid installing checkout-context@35.5.4. 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.