MAL-2026-13369 Malicious code in kepler (npm)

[email protected] declares its only runtime dependency, flag-serial-object-syntax, as an HTTP URL to a third-party host (https://artifacts.yosiroute.com/npm/flag-serial-object-syntax) rather than a version resolved from the npm registry, and the shrinkwrap marks that dependency with hasInstallScript: true. Running npm install kepler fetches an unpinned, unverified tarball from artifacts.yosiroute.com and executes its lifecycle scripts on the installer's machine. The URL carries no version and no integrity metadata, so its contents can change at any time under the third-party host's control. The kepler package itself has placeholder metadata (author Package Registry, repository github.com/example/...) unrelated to the yosiroute.com host, and ships no first-party code that would justify sourcing a dependency off-registry. The dependency-tree-hijack shape — an off-registry, mutable, install-scripted tarball pulled in transitively — means any code the operator of artifacts.yosiroute.com serves runs with the privileges of the installer on npm install.

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.