MAL-2026-17564 Malicious code in tostpro (npm)

Package [email protected] declares scripts.preinstall='sh./rce_poc.sh'. On install, the shipped shell script runs id/hostname/pwd and appends a timestamped line to./RCE_POC_MARKER.txt in the installer's working directory. The script performs no network I/O, reads no credentials or environment, writes nothing outside the install tree, and installs no persistence. The declared main entry dist/index.js is not shipped in the tarball, so the package has no library/import-time behavior; the preinstall marker write is its only effect. The README identifies the package as a security-research canary demonstrating dependency-confusion exposure for an internal name, consistent with the implausibly high version (99.101.0) used to win resolution against an internal package. The preinstall execution path is a real supply-chain concern in principle because a future version could replace the benign marker with a hostile payload, but this version's shipped payload produces no attacker benefit and no destructive action against the installer.

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.