MAL-2026-6348 Malicious code in buffer-wrap-67d7 (npm)

The package declares a postinstall hook ("postinstall": "node run.js") that executes run.js automatically on npm install. run.js imports os, fs, http, https, and child_process, and collects host and user identity signals including os.hostname(), os.userInfo(), os.platform(), process.env.USER, and process.cwd(), alongside filesystem reads (fs.existsSync, fs.readFileSync). Collected data is base64-encoded (Buffer.from(...).toString('base64')) and POSTed out via http/https calls (multiple POST sites at run.js lines 131, 339, 346). The composition — automatic lifecycle trigger, system/user reconnaissance, base64 packaging, and outbound POSTs — is the canonical install-time exfiltration shape and produces direct attacker benefit (host fingerprinting and credential-adjacent data leaving the installer's machine).