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Malicious MAL-2026-6143 GHSA-89vx-wfvc-j58f

node-vfs-polyfill

npm package · versions 2.0.5, 2.0.7

Reported Jun 18, 2026 · Updated Jul 8, 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 (7fb213e524ed75dcb54961d6d2ee9431ea6a32f4fdcb9d777bc260102920d81b)
On install, postinstall.js executes automatically and exfiltrates host reconnaissance data to attacker-controlled subdomains on oastify.com (Burp Collaborator), a domain commonly used for out-of-band data exfiltration. The script imports http, https, os, and child_process; calls os.hostname() and execSync() to gather system identifiers; and POSTs the collected data — including hostname, username, and version fields — to hardcoded endpoints such as http://xxxxxxxxx.oastify.com and http://rni4z9qkil62r9dcwosokhtgo7u9i76w.oastify.com. The package name suggests a generic VFS polyfill but the postinstall does no polyfill work; its sole observable effect on `npm install` is system-info exfiltration. This matches the dependency-confusion / reconnaissance beacon pattern.

Source: ghsa-malware (4832b15179ef6a8eaa9d826ce2778cac4debcf19c245bb08ae72d013802f3aca)
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.