MAL-2026-10115 Malicious code in fmt-date-lite (npm)

The npm package fmt-date-lite is a supply-chain dropper disguised as a benign date-formatting utility (its description reads "Lightweight date formatting utility with locale support"). It ships six files, no source repository and no dependencies, with its real behaviour in an install script.

A postinstall lifecycle hook (postinstall: node postinstall.js) executes automatically on npm install, before the package is ever imported. The install script fetches a second-stage payload from the hardcoded external endpoint 155.190.124.243:6788 and executes it via a Node child process (child_process / execSync) — the classic download-and-execute pattern. Any developer workstation or CI runner that installs the package (directly or transitively) hands arbitrary code execution to the operator of that endpoint.

fmt-date-lite is part of a coordinated campaign of near-identical "date/time formatting utility" droppers: sibling packages reuse the same shell and point at raw-IP infrastructure in the same 115-155.190.124.0/8 neighbourhood — e.g. datefmt-helper (C2 115.190.124.243) and date-fns-lite (C2 115.190.124.243, catalogued as OSV MAL-2026-6722).

On npm install, the package's postinstall lifecycle script runs the id command and transmits the resulting user/group identity to a hardcoded bare-IP endpoint at http://155.190.124.243:6788/ over plain HTTP. Three fallback delivery mechanisms are used (node http.get, curl, wget) to maximize the chance of successful exfiltration across environments. This behavior has no legitimate connection to the package's advertised purpose (a date-formatting utility), and the benign-sounding name and date-fns-lite authorship function as cover for the install-time beacon — consistent with a lure/typosquat targeting the date-fns ecosystem. The id output reveals the installer's username, UID, GID, and group memberships, providing reconnaissance for follow-on attacks and confirming the callback for the operator.