Which versions of node-vfs-polyfill are malicious?

The following npm versions of node-vfs-polyfill are flagged malicious: 2.0.5, 2.0.7. Treat any of these as compromised.

How do I remediate node-vfs-polyfill if I installed it?

node-vfs-polyfill is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.

I already installed node-vfs-polyfill — how do I know if it already compromised me?

If node-vfs-polyfill was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.

Is node-vfs-polyfill part of a known attack campaign?

Yes — node-vfs-polyfill is associated with the IN-MAL-2026-007039, GHSA-89vx-wfvc-j58f, IN-MAL-2026-008292 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find node-vfs-polyfill across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for node-vfs-polyfill (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging node-vfs-polyfill across your stack and pipelines.

Malicious package

node-vfs-polyfillnpm

node-vfs-polyfill is a confirmed malicious npm package (MAL-2026-6143) that steals credentials and exfiltrates sensitive data (malicious versions 2.0.5, 2.0.7). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in node-vfs-polyfill (npm)

MAL-2026-6143

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall node-vfs-polyfill

What this malware does

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.

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.

Malicious versions

2 flagged

2.0.52.0.7

Indicators of compromise (SHA-256)

7fb213e524ed75dcb54961d6d2ee9431ea6a32f4fdcb9d777bc260102920d81b

4832b15179ef6a8eaa9d826ce2778cac4debcf19c245bb08ae72d013802f3aca

12549502320678af61996b0eaa42c168a16ba359c2dbfaa10fce8d3ad600923d

Detection & response playbook

Credential / info stealer

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for node-vfs-polyfill (2 malicious versions). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging node-vfs-polyfill across your stack and pipelines.
If you installed it — respond
node-vfs-polyfill is built to steal secrets, so assume every credential the build or runtime could read is compromised. Remove it from your project and lockfile, then rotate ALL exposed secrets — npm/registry tokens, cloud keys, CI/CD secrets, SSH keys, and any .env values — from a known-clean machine. Audit logs for unauthorized use of those credentials.
Did it already run?
If node-vfs-polyfill was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks node-vfs-polyfill before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.

Frequently asked questions

No. node-vfs-polyfill on npm has been identified as a malicious package (versions 2.0.5, 2.0.7 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-007039GHSA-89vx-wfvc-j58fIN-MAL-2026-008292

References

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks node-vfs-polyfill-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the credential exfiltration and severs the channel.

Malware detection Runtime egress monitoring

Explore

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