# MAL-2026-11177: Malicious code in @peptide-unit/js-unimode (npm)


- **Type:** Malicious package
- **Package:** `@peptide-unit/js-unimode` (npm)
- **Published:** 29 Jul 2026
- **Also known as:** GHSA-hghj-5h7q-fq5h

## What is MAL-2026-11177?

MAL-2026-11177 is a malicious package in @peptide-unit/js-unimode, published on 29 Jul 2026. 

### Official description

index.js is a repackaged copy of the legitimate emptyport/unimod peptide-modification lookup library with an obfuscator.io RC4 string-array IIFE appended after the exported listMods function. On require(), the appended payload loads child_process, fs, os, path, and crypto, constructs a network URL keyed off the running Node major/minor/patch version, fetches a response, splits it on ':' into IV and ciphertext, AES-decrypts using a runtime-derived key (createDecipheriv + Buffer.from(iv,'hex')), writes the plaintext to a file under os.tmpdir() with writeFileSync flag 'w+', and invokes child_process exec on that file with cwd set to tmpdir and windowsHide disabled. The 336-entry rotating string array with base64+RC4 decoders (functions b/c) conceals the endpoint hostname, module names, and exec command. Package identity impersonates the legitimate emptyport/unimod project: package.json declares name @peptide-unit/js-unimode while homepage/repository point at github.com/emptyport/unimod and author is listed as Michael Porter — a scoped-name reupload with malicious payload grafted onto preserved legitimate exports (getByName/getById/listMods).

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-2026-11177?

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-2026-11177 is a malicious package: @peptide-unit/js-unimode (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-2026-11177/ (Markdown: https://insights.sbomify.com/MAL-2026-11177/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-11177

---
From sbomify Insights: https://insights.sbomify.com/MAL-2026-11177/
Summaries are generated and may contain mistakes; the official description above is the record.