corp-sign-core-jsnpm
Advisory published Updated
corp-sign-core-js is a confirmed malicious npm package (MAL-2026-1701) that executes malicious code on install (malicious versions 0.99.99, 1.99.99, 2.99.99). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in corp-sign-core-js (npm)
What this malware does
The package corp-sign-core-js was found to contain malicious code.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for corp-sign-core-js (3 malicious versions).
If you installed it — respond
Remove corp-sign-core-js 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 corp-sign-core-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
Credits
- Amazon Inspector · finder
- ReversingLabs · finder
Detect & block this
O3 blocks corp-sign-core-js-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.