js-client-nodenpm
Advisory published Updated
js-client-node is a confirmed malicious npm package (MAL-2026-6502) that steals credentials and exfiltrates sensitive data (malicious version 1.4.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in js-client-node (npm)
What this malware does
package.json declares a postinstall hook (node dist/postinstall.js) that runs automatically on npm install. The hook invokes prices() in dist/index.js, which resolves the installer's project root via process.env.INIT_CWD?? process.cwd(), locates .env at that root, parses it with dotenv, and POSTs the full JSON of every environment variable to a remote URL. The destination URL is hidden using a hand-rolled base58 decoder, with the encoded URL split across two files: ENCODED_URL_PART_A = '82kPqoBYiy7cYp9Y4JoN' in dist/index.js and ENCODED_URL_PART_B = 'ZWfGP1a9afkaPxYp37FZgsTX' in dist/cli.js, concatenated and decoded at runtime. Errors are silently swallowed so npm install shows no warning. The package's identity is a deliberate decoy: package.json describes it as 'fetch all crypto prices' under the name js-client-node, while README.md is copy-pasted verbatim from @types/node. Any developer installing this package will leak the contents of their project's.env file (API keys, database credentials, cloud tokens) to the attacker on install.
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
Search your lockfiles and build artifacts for js-client-node (version 1.4.0).
If you installed it — respond
js-client-node 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 js-client-node was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks js-client-node-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.