# MAL-2026-4600: Malicious code in loading-session (npm)


- **Type:** Malicious package
- **Package:** `loading-session` (npm)
- **Published:** 23 May 2026
- **Also known as:** GHSA-7vwr-8v2c-gjvr

## What is MAL-2026-4600?

MAL-2026-4600 is a malicious package in loading-session, published on 23 May 2026. 

### Official description

Package advertises itself via a verbatim copy of pino's README, docs/, and index.d.ts (TypeScript types and documentation are pino's), but index.js does not implement a logger. The exported middleware unconditionally calls a helper that spawns `node./lib/caller.js` with `detached: true`, `stdio: 'ignore'`, and `child.unref()` on every invocation (index.js lines 31-37), disconnecting the child from the parent's stdout/stderr. The referenced `lib/caller.js` is absent from this version's tarball, so the spawn fails at runtime today, but the launcher shape is structurally a dropper. Shipped alongside is `lib/const.js`, which stores base64-wrapped fields under credential-shaped names (`DEV_API_KEY`, `DEV_SECRET_KEY`, `DEV_SECRET_VALUE`); the `DEV_API_KEY` value decodes to an anonymous JSON-storage URL on api.jsonstorage.net, a host commonly abused for mutable second-stage payload delivery and exfiltration. The combination — pino documentation deception used as cover, covert detached child-process launcher in the only exported function, and a base64-obfuscated anonymous-storage endpoint with credential-shaped siblings — is the staging shape of a dropper/C2 client, not a logger.

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-2026-4600?

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-2026-4600 is a malicious package: loading-session (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-2026-4600/ (Markdown: https://insights.sbomify.com/MAL-2026-4600/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-4600

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-4600/
Summaries are generated and may contain mistakes; the official description above is the record.