@galicia-toolkit/error-masternpm
Advisory published Updated
@galicia-toolkit/error-master is a confirmed malicious npm package (MAL-2026-17689) that steals credentials and exfiltrates sensitive data (malicious version 999.0.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in @galicia-toolkit/error-master (npm)
What this malware does
@galicia-toolkit/[email protected] claims the @galicia-toolkit scope and describes itself as a dependency-confusion PoC. Its postinstall hook runs on npm install using node postinstall.js || true and sends encoded hostname, working-directory, platform, runtime-version, and username data as DNS labels to oob.s4yhii.com, making it a dependency-confusion probe that collects environment data. The npm account s4yhii_ published it on 2026-10-08.
On npm install, this package's postinstall script (node postinstall.js) hex-encodes the installer's hostname, current working directory, platform/arch/Node version, and USER/USERNAME/LOGNAME values, and emits DNS queries whose subdomains encode that data under the hardcoded author-controlled zone oob.s4yhii.com, using an authoritative resolver as an out-of-band exfiltration channel. The package name and the version number 999.0.3 are consistent with a dependency-confusion payload shape designed to win resolution against an internal @galicia-toolkit/error-master package. The DNS-tunnel beacon fires automatically at install time with no installer action beyond npm install, leaking host and user identifiers to the attacker's authoritative nameserver.
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 @galicia-toolkit/error-master (version 999.0.3).
If you installed it — respond
@galicia-toolkit/error-master 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 @galicia-toolkit/error-master 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
- InvisiRisk, Inc. · finder
Detect & block this
O3 blocks @galicia-toolkit/error-master-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.