mc-regnpm
mc-reg is a confirmed malicious npm package (MAL-2026-10637) that steals credentials and exfiltrates sensitive data (malicious versions 1.0.2, 1.0.3, 1.0.4…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in mc-reg (npm)
What this malware does
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.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for mc-reg (7 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging mc-reg across your stack and pipelines.
If you installed it — respond
mc-reg is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If mc-reg was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks mc-reg before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks mc-reg-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.