# MAL-2026-16484: Malicious code in pino-testkit (npm)


- **Type:** Malicious package
- **Package:** `pino-testkit` (npm)
- **Published:** 23 Sep 2026
- **Also known as:** GHSA-9q39-547h-rfpc

## What is MAL-2026-16484?

MAL-2026-16484 is a malicious package in pino-testkit, published on 23 Sep 2026. 

### Official description

pino-testkit@10.4.5 impersonates the widely-used `pino` logger: package.json declares the name `pino-testkit` with pino's description, lists Matteo Collina as author and the real pino maintainers as contributors, and the README is a mechanical copy of pino's README with `pino` rewritten to `pino-testkit`. The shipped source is largely a copy of pino with an extra file `lib/contract.js` wired in. `pino.js` exports `chain`, whose body calls `contract()`, so `require('pino-testkit')(...)` reaches the added file at load/call time. `lib/contract.js` uses a deterministic Fisher-Yates-style shuffle plus character substitution (`\x25`, `\x23\x30`, `\x23\x31`) to reconstruct the string `Function` and pluck `Function` off a captured global (`ype[OUN]`), then builds a new function from a second decoded body and immediately invokes it (`cMp(7746)`). Before doing so it hoists `require` and `module` onto `global`, so the dynamically constructed code can pull arbitrary further modules. Obfuscation of an executable payload combined with dynamic Function-constructor execution and require/module hoisting in a package that presents itself as `pino` is the canonical typosquat-dropper shape, giving the publisher arbitrary code execution on any consumer that requires or uses this package.

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-2026-16484?

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-2026-16484 is a malicious package: pino-testkit (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-2026-16484/ (Markdown: https://insights.sbomify.com/MAL-2026-16484/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-16484

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-16484/
Summaries are generated and may contain mistakes; the official description above is the record.