🛡️ MAL-2026-5686 — ecto-corsair-flag-x9m4

Malicious code in ecto-corsair-flag-x9m4 (npm)

Source: amazon-inspector

On npm install, postinstall.js executes attacker logic gated by hostname and working-directory checks designed to fire only inside CTF-style container environments (12-hex hostname, cwd under /app/, internal registry hosts like nexus.local/verdaccio) while suppressing execution in obvious analysis sandboxes (cwd containing /tmp/npm-safe or /tmp/pkg, hostname containing nijin/hetzner). When the gate matches, the script reads /app/flag.txt and other source files, spawns /bin/sh -c to recursively grep the filesystem for HTB{...} flag patterns, then POSTs {host, uid, cwd, data} to https://webhook.site/602a4c72-7033-4e28-92ea-dc66e59206e5 and PUTs the same data to http://154.57.164.82:31250. The hostname/cwd gating, the targeted flag-file path, and the dual exfiltration destinations together establish unambiguous malicious intent. Any installer matching the gate has CTF flag contents and host identifiers shipped to attacker infrastructure on install.

Source: ghsa-malware

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.