# MAL-2026-4799: Malicious code in pdf-lib-enhanced (npm)


- **Type:** Malicious package
- **Package:** `pdf-lib-enhanced` (npm)
- **Published:** 26 May 2026
- **Also known as:** GHSA-9qcm-qgjc-h848

## What is MAL-2026-4799?

MAL-2026-4799 is a malicious package in pdf-lib-enhanced, published on 26 May 2026. 

### Official description

Package name `pdf-lib-enhanced` mimics the widely-used `pdf-lib` library and ships a verbatim copy of upstream's README. `package.json` declares `repository.url` pointing at a fresh GitHub account (`harunosakura030303-maker/pdf-lib-enhanced`) while `bugs.url` still points at the original `Hopding/pdf-lib` project — a metadata mismatch consistent with a hastily-forked squat. The `dist/` directory contains unrelated SheetJS assets (`xlsx.full.min.js`, `xlsx.zahl.js`, `cpexcel.js`, etc.) that have no purpose in a PDF library. However, the CommonJS main entry (`cjs/index.js`) re-exports the upstream pdf-lib API without any credential reads, exfiltration, dropper, or silent-relay behavior, and `package.json` declares no `preinstall`/`install`/`postinstall`/`prepare` lifecycle scripts, so installing the package does not auto-execute any code. The dormant SheetJS bundles are not referenced from the main entry. Name-similarity to a top-tier package combined with an irrelevant payload bundle warrants human assessment of intent, but there is no concrete installer-harm mechanism observable in the shipped code.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.

## What should I do about MAL-2026-4799?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

## Fix prompt for AI coding agents

```text
MAL-2026-4799 is a malicious package: pdf-lib-enhanced (npm). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-4799/ (Markdown: https://insights.sbomify.com/MAL-2026-4799/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-4799

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-4799/
Summaries are generated and may contain mistakes; the official description above is the record.