MAL-2026-5979 Malicious code in easy-day-js (npm)
Malicious package
Published
MAL-2026-5979 is a malicious package: easy-day-js (npm). Every version was published to cause harm.
Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.
Reference: https://insights.sbomify.com/MAL-2026-5979/ (Markdown: https://insights.sbomify.com/MAL-2026-5979/index.md)
- Package
- easy-day-js
- Registry
- npm
What is MAL-2026-5979?
MAL-2026-5979 is a malicious package in easy-day-js, published on 17 Jun 2026.
Official description
Package name 'easy-day-js' impersonates the popular 'dayjs' library, copying dayjs's author ('iamkun'), homepage (https://day.js.org), repository URL, description, and version number (1.11.22 is a real dayjs release), and bundles dayjs.min.js as main to look legitimate. package.json adds a postinstall hook 'node setup.cjs –no-warnings' that does not exist in real dayjs. setup.cjs is heavily obfuscated with an obfuscator.io-style rotated base64 string array (a0_0x23bf) and decoder (a0_0x1a24) hiding API names ('node:child_process', 'node:fs', 'node:crypto', 'spawn', 'writeFileSync'). At install time it sets NODE_TLS_REJECT_UNAUTHORIZED='0' to disable TLS verification, writes the install directory path to os.tmpdir()/.pkg_history and an encoded buffer to os.tmpdir()/.pkg_logs (staging metadata for the second stage), fetches a JavaScript payload from https://23.254.164.92:8000/update/49890878, writes it to a random hex-named file in os.tmpdir(), spawns it detached with the installer's node interpreter (process.execPath, stdio:'ignore', unref()), and then unlinks setup.cjs to cover its tracks. Classic install-time remote-code-execution dropper combined with brand impersonation of dayjs.
What should I do about MAL-2026-5979?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.