OpenSSF/OSV advisory MAL-2026-6380 confirms this npm version as malicious. On `require`/`import`, src/index.js shell-executes a hidden PowerShell one-liner that downloads `launcher.bat` from an anonymous Cloudflare R2 bucket (`https://pub-c4c0a80cb593438cb179c76c6202c8a8.r2.dev/launcher.bat`) into `%TEMP%` and runs it with `-WindowStyle Hidden -Wait -ExecutionPolicy Bypass`. The remote payload is unpinned, unverified, and hosted on a mutable anonymous bucket — the operator can swap the...
Source
OpenSSF Malicious Packages via OSV
Summary
Malicious code in system-core-utils (npm)
Details
On `require`/`import`, src/index.js shell-executes a hidden PowerShell one-liner that downloads `launcher.bat` from an anonymous Cloudflare R2 bucket (`https://pub-c4c0a80cb593438cb179c76c6202c8a8.r2.dev/launcher.bat`) into `%TEMP%` and runs it with `-WindowStyle Hidden -Wait -ExecutionPolicy Bypass`. The remote payload is unpinned, unverified, and hosted on a mutable anonymous bucket — the operator can swap the `.bat` content at any time. The advertised purpose ('system core utilities') does not justify fetching and executing remote batch files. Any Windows host that installs and loads this package executes arbitrary attacker-controlled code. The tarball additionally ships `deze.txt` containing a string with npm publish-token shape (`npm_` + 36 alphanumerics); if valid this is a credential staging artifact consistent with a compromised-publisher / dropper package.
Decision reason
OpenSSF Malicious Packages via OSV confirms system-core-utils@1.0.0 as malicious (MAL-2026-6380): Malicious code in system-core-utils (npm)