@array-util/subsearchnpm
Advisory published Updated
@array-util/subsearch is a confirmed malicious npm package (MAL-2026-11095) that steals credentials and exfiltrates sensitive data (malicious version 1.0.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in @array-util/subsearch (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 in a published npm library — particularly one whose advertised purpose ('subsearch' array utility) would not require it — is a notable signal because legitimate utility libraries are typically shipped readable or minified-but-not-string-array-encoded. However, the actual decoded behavior of the file has not been confirmed, and obfuscation alone is not proof of installer-side harm. Routing to human review so a reviewer can de-obfuscate index.js and verify whether the decoded code performs exfiltration, dropping, or silent-relay before any block decision.
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 @array-util/subsearch (version 1.0.3).
If you installed it — respond
@array-util/subsearch 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 @array-util/subsearch 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 @array-util/subsearch-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.