# MAL-2026-15918: Malicious code in @modss/baileys (npm)


- **Type:** Malicious package
- **Package:** `@modss/baileys` (npm)
- **Published:** 3 Sep 2026
- **Also known as:** GHSA-4c9v-m7qm-2mpr

## What is MAL-2026-15918?

MAL-2026-15918 is a malicious package in @modss/baileys, published on 3 Sep 2026. 

### Official description

@modss/baileys is a renamed fork of the Baileys WhatsApp Web library published 2026-09-01 and 2026-09-02 under a scope created the same day. lib/Socket/newsletter.js sets NEWSLETTER_LIST_URL to https://raw.githubusercontent.com/Dayyy-19/Anu/main/Newsletter.json. On every connection.update with connection === 'open', autoFollowConfiguredNewsletters() fetches that list and issues an executeWMexQuery FOLLOW for each id on the user's own authenticated WhatsApp session, caching followed ids in session/followed-newsletters.json. An Indonesian comment in the file explains that the list lives on GitHub so channels can be added or removed without redeploying the code, i.e. the follow targets are publisher-controlled at runtime. All three published versions carry the identical handler. The package also aliases its libsignal dependency to @modss/libsignal, which pkgwarden read as a plain rename with no malicious content. No credential or session-key theft was observed, and the dead-drop URL was not requested by pkgwarden. All versions were fetched from the npm registry and read by hand on 2026-09-03. Same remote-dead-drop shape as MAL-2026-15819 (@mrlegendbot/baileys) and MAL-2026-13932 (my-auto-follow).

package.json declares a runtime dependency `libsignal` whose source is `github:RILLYZY/libsignal-node` — a GitHub reference with no commit SHA, tag, or version pin. On `npm install`, npm fetches whatever HEAD of that personal repository currently returns and runs any lifecycle scripts it contains on the installer's machine, with no integrity check. Whoever controls that GitHub account controls code that executes on any machine installing @modss/baileys, and the fetched content can change silently between installs. The named dependency also shadows the legitimate `libsignal` cryptographic library, meaning callers of the package's signal-protocol paths load code from the unpinned third-party fork rather than a registry-audited artifact.

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-2026-15918?

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-2026-15918 is a malicious package: @modss/baileys (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-2026-15918/ (Markdown: https://insights.sbomify.com/MAL-2026-15918/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-15918

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-15918/
Summaries are generated and may contain mistakes; the official description above is the record.