OpenSSF/OSV advisory MAL-2026-10637 confirms this npm version as malicious. 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'`...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in mc-reg (npm)
Details
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.
## Source: ghsa-malware (7bc757c5a8198ec3a1d2e2be1f483da8abeaea6d5565febbb22ef1bf1e4eb6d0) 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.
Decision reason
OpenSSF Malicious Packages via OSV confirms mc-reg@1.0.5 as malicious (MAL-2026-10637): Malicious code in mc-reg (npm)