@gocortexio/npmgremlinbox-malware-c2-beaconnpm
Advisory published Updated
@gocortexio/npmgremlinbox-malware-c2-beacon is a confirmed malicious npm package (MAL-2026-10832) that opens a backdoor for remote access. Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in @gocortexio/npmgremlinbox-malware-c2-beacon (npm)
What this malware does
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
Every published version of this package is considered malicious — remove it entirely.
Indicators of compromise (SHA-256)
Detection & response playbook
Backdoor / remote accessFind it
Search your lockfiles and build artifacts for @gocortexio/npmgremlinbox-malware-c2-beacon (all published versions).
If you installed it — respond
@gocortexio/npmgremlinbox-malware-c2-beacon establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If @gocortexio/npmgremlinbox-malware-c2-beacon 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
Detect & block this
O3 blocks @gocortexio/npmgremlinbox-malware-c2-beacon-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.