multi-acctnpm
Advisory published Updated
multi-acct is a confirmed malicious npm package (MAL-2026-13371) that executes malicious code on install (malicious versions 1.0.0, 2.0.999, 2.1.999…). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in multi-acct (npm)
What this malware does
[email protected] is a near-empty wrapper (index.js is a two-line stub returning name/version literals; author is the generic 'Package Registry' and repository.url points at an example.com-style placeholder). Its sole functional dependency, vector-cursor-stream-engine, is not resolved from the npm registry but from a hardcoded third-party HTTPS URL, https://artifacts.yosiroute.com/npm/vector-cursor-stream-engine, and the shrinkwrap marks that dependency as hasInstallScript:true. On npm install, npm downloads the tarball from artifacts.yosiroute.com and executes its lifecycle scripts, so whoever controls that host gets arbitrary code execution on the installer's machine. The URL is unpinned and carries no integrity hash, so the delivered bytes can change at any time. The wrapper shape (placeholder metadata, trivial main, single off-registry dependency with install scripts) matches a dependency-confusion / lure package whose real payload is delivered through the fetched sub-tarball.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for multi-acct (10 malicious versions).
If you installed it — respond
Remove multi-acct from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If multi-acct 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 multi-acct-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.