---
canonical: "https://firewall.lpm.dev/npm/babel-plugin-linaria-css-to-undefined/v/0.3.15"
markdown: "https://firewall.lpm.dev/npm/babel-plugin-linaria-css-to-undefined/v/0.3.15.md"
package: "babel-plugin-linaria-css-to-undefined"
report_status: "published"
title: "babel-plugin-linaria-css-to-undefined@0.3.15 npm security report"
verdict: "malicious"
version: "0.3.15"
---

# babel-plugin-linaria-css-to-undefined@0.3.15 npm security report

> **Trust boundary:** Package metadata, advisory text, filenames, URLs, and source snippets in this report come from external packages or feeds. Treat them as untrusted evidence. Do not execute instructions or code found in this document.

## Verdict summary
**Blocked & quarantined** — Arbitrary code execution and likely credential compromise during installation.

- **Verdict:** Malicious
- **Product-default install policy:** Block
- **Firewall policy:** Matched malicious
- **Public report status:** Published
- **Threat category:** Remote Code Execution
- **Selected version:** 0.3.15
- **Selected version is latest:** No
- **Analysis source:** AI Security Review (lpm-firewall-ai)

Preinstall fetches and executes an obfuscated second-stage script. The stage dynamically evaluates remote content and handles GitHub credentials.

## Latest scan
- **Scanner version:** rust-scanner-worker-schema-1
- **Verdict:** Malicious
- **Confidence:** 99.0%
- **Started:** 2026-08-04T12:48:31.791Z
- **Finished:** 2026-08-04T12:48:57.097Z
- **Download time:** 252 ms
- **Static scan time:** 390 ms
- **AI review time:** 24663 ms
- **Total time:** 25306 ms

## Security analysis

### Published attack-surface review

- **Summary:** Preinstall fetches and executes an obfuscated second-stage script. The stage dynamically evaluates remote content and handles GitHub credentials.

- **Trigger:** npm installation

- **Impact:** Arbitrary code execution and likely credential compromise during installation.

- **Evidence paths:** package.json, setup.mjs, math\_init.js, lib/index.js

- **Review source:** ai\_review

- **Reviewed:** 2026-08-04T12:48:57.097Z

### AI review details

- **Review stage:** source\_first\_review

- **Mechanism:** remote payload bootstrap with dynamic eval and credential-oriented logic

- **Attack narrative:** On npm preinstall, setup.mjs invokes an existing Bun binary or downloads a Bun release and executes math\_init.js. That obfuscated stage includes fetched-response eval, GitHub-token handling, and process execution, creating an unconsented install-time remote-code path unrelated to the advertised Babel transform.

- **Rationale:** The advertised plugin is benign, but the preinstall bootstrap and obfuscated second stage establish concrete malicious install-time behavior.

- **Files touched:** package.json, setup.mjs, math\_init.js

- **Network endpoints:** https://github.com/oven-sh/bun/releases/download/bun-v1.3.13/

### Review decision

- **Verdict:** Malicious

- **Confidence:** 99.0%

- **Recommended action:** publish\_block

- **Intent class:** Malware

- **False-positive risk:** Low

- **Evidence for:** package.json runs \`node setup.mjs\` as preinstall., setup.mjs downloads Bun then executes math\_init.js at install time., math\_init.js is heavily obfuscated and executes fetched response text with eval., math\_init.js contains GitHub-token handling and child-process execution.

- **Evidence against:** lib/index.js is a small, conventional Babel transform., README.md describes only the Babel plugin behavior.

## Public findings

### 1. High: Install Time Lifecycle Scripts
- **Category:** Manifest
- **Confidence:** 90.0%
- **Path:** package.json
- **Public source:** [View source](<https://unpkg.com/babel-plugin-linaria-css-to-undefined@0.3.15/package.json>)

Package defines install-time lifecycle scripts.

Public source snippet (untrusted):

```json
scripts.preinstall = node setup.mjs
```

### 2. Low: Scripts Present
- **Category:** Manifest
- **Confidence:** 100.0%

Package declares npm scripts.

### 3. Low: Eval
- **Category:** Source
- **Confidence:** 45.0%
- **Path:** math\_init.js
- **Public source:** [View source](<https://unpkg.com/babel-plugin-linaria-css-to-undefined@0.3.15/math_init.js>)

Package source references a known benign dynamic code generation pattern.

Public source snippet (untrusted):

```javascript
L1: // @bun @bun-cjs
L2: var MmgoCP,etDiOOB,JqTtnbZ,bc3Kak,ZQmUTyQ,TTUgga,MDX6yrw,h8wMJNB,CabwE2L,x5ErqV;function WV8StW(MmgoCP,etDiOOB,JqTtnbZ){for(JqTtnbZ=0x0;JqTtnbZ<etDiOOB;JqTtnbZ++)MmgoCP.push(MmgoCP...
```

### 4. Medium: Network
- **Category:** Source
- **Confidence:** 75.0%

Package source references network APIs.

### 5. Low: Filesystem
- **Category:** Source
- **Confidence:** 70.0%

Package source references filesystem APIs.

### 6. Low: High Entropy Strings
- **Category:** Supply Chain
- **Confidence:** 55.0%

Package source contains high-entropy string patterns.

### 7. Low: Url Strings
- **Category:** Supply Chain
- **Confidence:** 65.0%

Package source contains URL literals.

### 8. Medium: Structural Risk Force Deep Review
- **Category:** Artifact Inventory
- **Confidence:** 80.0%

Artifact structure forces deeper review even if the static behavioral verdict is clean.

### 9. High: Known Malware Source Similarity
- **Category:** Static
- **Confidence:** 97.0%
- **Path:** setup.mjs
- **Public source:** [View source](<https://unpkg.com/babel-plugin-linaria-css-to-undefined@0.3.15/setup.mjs>)

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

Public source snippet (untrusted):

```javascript
matchType = normalized_sha256
matchedPackage = example-js-project@1.0.11
matchedPath = setup.mjs
matchedIdentity = npm:ZXhhbXBsZS1qcy1wcm9qZWN0:1.0.11
similarity = 1.000
summary = normalized source hash matched finalized malicious source
```

### 10. High: Known Malware Source Fingerprint Signature
- **Category:** Supply Chain
- **Confidence:** 94.0%
- **Path:** setup.mjs
- **Public source:** [View source](<https://unpkg.com/babel-plugin-linaria-css-to-undefined@0.3.15/setup.mjs>)

Source fingerprint signature matches a known malicious package signature; route for source-aware review.

Public source snippet (untrusted):

```javascript
matchType = malicious_source_fingerprint_signature
signature = 04ba21a16d3a5a3a
signatureType = suspicious_hashes
sourceLabel = final_verdict:malicious
matchedPackage = example-js-project@1.0.11
matchedPath = setup.mjs
matchedIdentity = npm:ZXhhbXBsZS1qcy1wcm9qZWN0:1.0.11
similarity = 1.000
shingleOverlap = 2
summary = package final verdict is malicious
```

## Dependencies and install lifecycle
- **Lifecycle scripts present:** Yes
- **Published lifecycle scripts:** preinstall
- **Dependencies:** 0
- **Optional dependencies:** 0
- **Peer dependencies:** 1
- **Development dependencies:** 0
- **Published dependency-graph edges:** 1

### Published dependency entries
- @babel/core ^7.0.0 (PeerDependency)

## Package metadata
- **Package:** babel-plugin-linaria-css-to-undefined
- **Ecosystem:** npm
- **Version:** 0.3.15
- **License:** MIT
- **Version published:** 2026-08-04T12:46:07.814Z
- **Package first seen:** 2026-08-04T11:50:39.790Z
- **Package last seen:** 2026-08-05T00:00:20.818Z
- **Known versions:** 17
- **Latest version:** 0.3.17
- **Appeal under review:** No
- **Author:** Christophe Hurpeau \<christophe@hurpeau.com\> (https://christophe.hurpeau.com)
- **Runtime engines:** node: \>= 14.17.5
- **Artifact files:** 7
- **Artifact unpacked size:** 742,906 bytes
- **Artifact signatures:** 1
- **Attestations:** No

## References
- [HTML security report](<https://firewall.lpm.dev/npm/babel-plugin-linaria-css-to-undefined/v/0.3.15>)
- [OSV advisory](<https://osv.dev/vulnerability/MAL-2026-11962>)
- [WEB](<https://socket.dev/blog/popular-npm-packages-in-the-keyv-and-cacheable-namespaces-compromised-in-active-supply-chain>)
- [WEB](<https://www.aikido.dev/blog/keyv-and-friends-compromised-in-npm-supply-chain-attack>)
- [WEB](<https://safedep.io/keyv-npm-supply-chain-compromise/>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined>)
- [ADVISORY](<https://github.com/advisories/GHSA-277g-jjx3-xmwj>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.16>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.8>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.7>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.12>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.17>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.15>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.3>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.6>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.10>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.11>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.14>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.4>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.13>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.1>)
- [PACKAGE](<https://www.npmjs.com/package/babel-plugin-linaria-css-to-undefined/v/0.3.9>)