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OpenAdvisories
Malicious MAL-2026-14166

chalk-es

npm package · versions 1.0.0

Reported Aug 18, 2026 · Updated Aug 19, 2026

If this package is installed

Remove it, treat the machine (or CI runner) as compromised, and rotate every secret, token and key it could access — from a different, clean machine.

Details

Source: amazon-inspector (9a278b0c90f55a6a518b61ec1c964468011d1e4be184df5f36336a5f82ea58cc)
Package name mimics `chalk` but ships an empty library body; the only real behavior lives in `scripts/postinstall.js`. On install the script XOR-decodes (key `stf2026`) a hardcoded GitHub URL and downloads a Windows binary to `%TEMP%\main.exe`, then spawns it detached. On WSL/Linux hosts an XOR-decoded bridge command is exec'd to reach the underlying Windows host and run the same payload from inside Linux. The postinstall also POSTs a JSON body containing the resolved platform label (with WSL detection) to a hardcoded bare-IP endpoint at `http://193.70.34.101:20099/vote`, serving as an install beacon/victim tracker. Four byte-array constants (ADDON_ENC, BRIDGE_LAUNCHER_ENC, BRIDGE_SCRIPT_PRE_ENC, BRIDGE_SCRIPT_POST_ENC) are XOR-decoded at runtime specifically to hide the fetch URL and the Windows/WSL execution command.