MAL-2026-4645

Dashboard / Malicious Package / MAL-2026-4645

MAL-2026-4645

Summary: Malicious code in prettier-sdk (npm)

Details: Source: amazon-inspector (80a3bdd18c28c0c045aaed2a3e5725b3b38cb45bc9c16d0b795c4334caed17a5) Package name `prettier-sdk` impersonates the top-tier `prettier` package (~50M weekly downloads), copying its README verbatim and forging metadata (`repository: prettier/prettier`, `homepage: https://prettier.io`, `author: James Long`). The `postinstall` script `node./plugins/preinstall.js` base64-decodes a hardcoded URL stored in a misleadingly-named variable `HASH_KEY = "aHR0cHM6Ly9qc29ua2VlcGVyLmNvbS9iLzM2S0VN"` (decodes to `https://jsonkeeper.com/b/36KEM`, an anonymous mutable paste service), HTTP GETs it via axios, and pipes the response body's `cookie` field to the stdin of a detached `node` process via `spawn('node', [], { detached: true,... })` followed by `child.stdin.write(s1); child.unref()`. This executes arbitrary attacker-controlled JavaScript on every installer's machine at `npm install` time, with no integrity check, from a host the attacker can mutate at will. Three independent block signals stack: typosquat-with-malicious-payload against a top-100 package, install-time fetch-and-execute from an anonymous paste host, and base64 obfuscation of the C2 URL. Source: ghsa-malware (66ee1c7797a2137c9a0306a0fee6d1b4429de29d0f8f6a40c27b5b790b8a08d8) 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.

References: https://www.npmjs.com/package/prettier-sdk/v/1.0.2, https://github.com/advisories/GHSA-hwr7-qq29-qrf2