Which versions of css-ogojwh-polyfill are malicious?

The following npm versions of css-ogojwh-polyfill are flagged malicious: 1.0.0. Treat any of these as compromised.

How do I remediate css-ogojwh-polyfill if I installed it?

css-ogojwh-polyfill establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.

I already installed css-ogojwh-polyfill — how do I know if it already compromised me?

If css-ogojwh-polyfill was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Is css-ogojwh-polyfill part of a known attack campaign?

Yes — css-ogojwh-polyfill is associated with the IN-MAL-2026-021017 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 css-ogojwh-polyfill across my projects, lockfiles, and CI pipelines?

Search your lockfiles and build artifacts for css-ogojwh-polyfill (version 1.0.0).

Malicious package

css-ogojwh-polyfillnpm

Advisory published Oct 5, 2026Updated Oct 5, 2026

css-ogojwh-polyfill is a confirmed malicious npm package (MAL-2026-17556) that opens a backdoor for remote access (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in css-ogojwh-polyfill (npm)

MAL-2026-17556

Immediate action

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

npm uninstall css-ogojwh-polyfill

What this malware does

[email protected] presents itself as a CSS polyfill but ships thunderboltRegistry.js which, on require, runs an IIFE that executes shell commands via child_process.execSync (id, whoami, uname -a, ifconfig/ip addr, cat /etc/hosts) and POSTs their output along with hostname, Node version, platform and pid to the hardcoded endpoint http://dxpoc.gt.tc/callback.php/bb8968d0f67000433bf7005dd5ad2d1f, with a beacon label of rce-poc. The module also exports no-op Proxy stubs under module names matching Wix thunderbolt registry modules (thunderboltRegistry, siteAssetsRegistry, editorRegistry), consistent with a dependency-confusion / typosquat shim whose only real behavior is the recon-and-exfil payload executed at import time.

Malicious versions

1 flagged

1.0.0

Indicators of compromise (SHA-256)

aff543635c832e0563229f42fcc7673c835f2ba5a9ae41d680aa572cfba49765

Detection & response playbook

Backdoor / remote access

Find it
Search your lockfiles and build artifacts for css-ogojwh-polyfill (version 1.0.0).
If you installed it — respond
css-ogojwh-polyfill establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If css-ogojwh-polyfill was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

Frequently asked questions

No. css-ogojwh-polyfill on npm has been identified as a malicious package (version 1.0.0 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-021017

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks css-ogojwh-polyfill-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.

Malware detection Runtime egress monitoring

Explore

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