# MAL-2026-10637: Malicious code in mc-reg (npm)


- **Type:** Malicious package
- **Package:** `mc-reg` (npm)
- **Published:** 15 Jul 2026
- **Also known as:** GHSA-hvhc-6qpw-v5r9

## What is MAL-2026-10637?

MAL-2026-10637 is a malicious package in mc-reg, published on 15 Jul 2026. 

### Official description

mc-reg advertises itself as a Cosmos chain-registry data package (README shows chain-registry-style `assets`/`chains`/`ibc` API), but its main and ESM entrypoints do not expose that data. Instead, index.js lazy-imports and re-exports `PartnerVaultHttpProvider` from an unrelated runtime dependency `chain-sdk-js`, and esm/index.js statically imports it — so `require('mc-reg')` or `import { chains } from 'mc-reg'` transparently pulls chain-sdk-js into the consumer's dependency tree. The pulled dependency's `persistence/chain.js` contains a wallet-secret interception + exfiltration pattern: a hardcoded destination reconstructed from a char-code array (`ping`/`ping`/`ping` decode-and-join sequence at lines 320-322 / 322-324) and POST calls (lines 118/204 and 120/206) that ship data to a non-caller-configured host, matching the shape of BIP-39 mnemonic / private-key theft from a wallet/signing path. The mc-reg package itself is a lure whose only effect on install/import is to route consumers into the malicious chain-sdk-js code path under the guise of a benign chain-registry data 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-2026-10637?

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-2026-10637 is a malicious package: mc-reg (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-2026-10637/ (Markdown: https://insights.sbomify.com/MAL-2026-10637/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-10637

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-10637/
Summaries are generated and may contain mistakes; the official description above is the record.