# MAL-2026-13461: Malicious code in supersig (npm)


- **Type:** Malicious package
- **Package:** `supersig` (npm)
- **Published:** 6 Aug 2026
- **Also known as:** GHSA-vjp6-7fgj-3cgm

## What is MAL-2026-13461?

MAL-2026-13461 is a malicious package in supersig, published on 6 Aug 2026. 

### Official description

The published dist bundles (dist/supersig.cjs.js, dist/supersig.esm.js, dist/supersig.umd.js), reached via the package's main/module/browser entries on require/import, contain a decrypt-and-execute chain that is absent from the src/ tree. The bundles import a DES key from an unpinned dependency mkb-manager@latest, call decryptToken on an embedded encrypted token to produce plaintext code, spawn a fresh node child process via child_process.spawn('node', [],...), and write the decrypted bytes into that process's stdin (rsa_exec.stdin.write / des_exec.stdin.write). Any consumer that requires or imports this package executes the decrypted payload at load time. Because mkb-manager is pinned to latest, whoever controls that package can rotate the decryption key/payload at will, making the executed code opaque and mutable. The src/ wallet, signers, providers, and transactions modules contain no decryptToken, readRSAFromPackage, mkb-manager, or child_process usage — the dropper is present only in the shipped bundles, indicating deliberate concealment from source-tree review.

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-2026-13461?

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-2026-13461 is a malicious package: supersig (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-2026-13461/ (Markdown: https://insights.sbomify.com/MAL-2026-13461/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13461

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-13461/
Summaries are generated and may contain mistakes; the official description above is the record.