eslint-plugin-mistica-local-rulesnpm
Advisory published Updated
eslint-plugin-mistica-local-rules is a confirmed malicious npm package (MAL-2026-5703) that steals credentials and exfiltrates sensitive data (malicious version 19.12.11). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in eslint-plugin-mistica-local-rules (npm)
What this malware does
package.json declares a preinstall hook that runs index.js automatically on npm install. index.js collects host identity (os.hostname(), os.platform(), os.arch(), os.userInfo() including uid/gid, shell, homedir, cwd) and the output of whoami and id via child_process, then POSTs the JSON payload to the hardcoded URL https://eucfugc8bk66haszliir75yd74dv1lpa.oastify.com/detox56 (a Burp Collaborator subdomain). The package ships no eslint rule implementation — its only effect on install is the recon/exfiltration beacon. The package name eslint-plugin-mistica-local-rules mimics the Telefónica Mistica design-system internal eslint-plugin namespace, consistent with a dependency-confusion attack against private-registry consumers.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Credential / info stealerFind it
Search your lockfiles and build artifacts for eslint-plugin-mistica-local-rules (version 19.12.11).
If you installed it — respond
eslint-plugin-mistica-local-rules 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 eslint-plugin-mistica-local-rules 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 eslint-plugin-mistica-local-rules-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.