xnder-sdk-jsnpm
Advisory published Updated
xnder-sdk-js is a confirmed malicious npm package (MAL-2026-6906) that steals credentials and exfiltrates sensitive data (malicious version 0.1.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in xnder-sdk-js (npm)
What this malware does
The package's index.js is heavily obfuscated (string-array shift/rotate pattern with hex-encoded indices and a while(!![]) decoder loop). Obfuscation of the main module hides intent and prevents automated tracing of behavior at require time. No concrete installer-harm mechanism (exfiltration endpoint, dropper, credential read, lifecycle script) was identified in the available evidence, so the obfuscation alone is not sufficient to confirm an attack, but it is also inconsistent with the typical shape of a legitimate SDK that is shipped readable or as a standard minified bundle with source maps. Manual de-obfuscation of index.js is required before installer trust can be granted.
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 xnder-sdk-js (version 0.1.0).
If you installed it — respond
xnder-sdk-js 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 xnder-sdk-js 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 xnder-sdk-js-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.