registry / Credential exfiltration / fca-nx / 6.6.9

fca-nx@6.6.9

Facebook Messenger API for Node.js — Fast, Secure, and Feature-Rich

AI Security Review

scanned 1mo ago · by lpm-firewall-ai

No install-time hook, self-dependency, hidden downloader, or package-controlled non-Facebook receiver was found. The environment-controlled DGW path nonetheless forwards session cookies to arbitrary URLs when enabled, leaving a concrete unresolved credential-exfiltration risk.

Static reason

High-risk behavior combination matched malicious policy.; source matched previously finalized malicious package; routed for review; previous stored version diff introduced dangerous source

Trigger

A login initializes E2EE, with E2EE enabled and FB_DGW_ENABLE plus a FB_DGW_URL_* variable set.

Impact

An entity able to control that process environment could receive the user's Facebook session cookies.

Mechanism

Environment-selected WebSocket connection carrying session cookies.

AI rationale

Evidence

e2ee/vendor/fb-e2ee.cjsmodule/loginHelper.js.fca-nx/e2ee_device.json

Network endpoints3

process.env.FB_DGW_URL_LIGHTSPEEDprocess.env.FB_DGW_URL_STREAMCONTROLLERprocess.env.FB_DGW_URL_REALTIME

Decision evidence

public snapshot

AI called this Suspicious at 84.0% confidence as Dangerous Capability with medium false-positive risk.

Evidence for warning

The optional DGW path sends the logged-in session cookie header to endpoints supplied through environment variables.
The package automatically invokes its E2EE connection during login; the DGW feature can run after E2EE connects when its environment switch is set.

Evidence against

package.json has no preinstall, install, postinstall, or prepare hook.
E2EE activation is normally gated by an explicit config flag or option.
The ordinary E2EE endpoints are Facebook and Messenger hosts, matching this Messenger API package.
Remote-control networking is disabled in the default project configuration.

Behavioral surface

Source

ChildProcessCryptoDynamicRequireEnvironmentVarsEvalFilesystemNetworkWebSocket

Supply chain

HighEntropyStringsUrlStrings

ManifestNo manifest risk signals triggered.

Source & flagged code

15 flagged

e2ee/vendor/fb-e2ee.cjsView file

Lines 110-150javascript

110var require_safe_buffer = __commonJS({

111 "node_modules/ws/node_modules/safe-buffer/index.js"(exports2, module2) {

112 "use strict";

113 init_cjs_shims();

114 var buffer = require("buffer");

115 var Buffer3 = buffer.Buffer;

116 function copyProps(src, dst) {

117 for (var key in src) {

118 dst[key] = src[key];

119 }

120 }

121 if (Buffer3.from && Buffer3.alloc && Buffer3.allocUnsafe && Buffer3.allocUnsafeSlow) {

122 module2.exports = buffer;

123 } else {

124 copyProps(buffer, exports2);

125 exports2.Buffer = SafeBuffer;

126 }

127 function SafeBuffer(arg, encodingOrOffset, length) {

128 return Buffer3(arg, encodingOrOffset, length);

129 }

130 copyProps(Buffer3, SafeBuffer);

131 SafeBuffer.from = function(arg, encodingOrOffset, length) {

132 if (typeof arg === "number") {

Critical

Hardcoded Runtime Data Exfiltration

Source sends credentials or rich application records to a package-controlled external receiver enabled by default.

e2ee/vendor/fb-e2ee.cjsView on unpkg · L130

Low

Weak Crypto

Package source references weak cryptographic algorithms.

e2ee/vendor/fb-e2ee.cjsView on unpkg · L130

133 throw new TypeError("Argument must not be a number");

134 }

135 return Buffer3(arg, encodingOrOffset, length);

136 };

137 SafeBuffer.alloc = function(size, fill, encoding) {

138 if (typeof size !== "number") {

139 throw new TypeError("Argument must be a number");

140 }

141 var buf = Buffer3(size);

142 if (fill !== void 0) {

143 if (typeof encoding === "string") {

144 buf.fill(fill, encoding);

145 } else {

146 buf.fill(fill);

147 }

148 } else {

149 buf.fill(0);

150 }

Lines 2944-2984javascript

2944 "kyc-id",

2945 "privacy_token",

2946 "readreceipts",

2947 "appointment_only",

2948 "address",

2949 "expected_ts",

2950 "privacy",

2951

e2ee/index.jsView file

Lines 125-165javascript

125(function _polyfillFileGlobal() {

126 try {

127 if (typeof globalThis.File === "undefined") {

128 var b = require("buffer"

e2ee/protocol.jsView file

Lines 1-34javascript

1"use strict";

3/**

4 * Facebook-specific E2EE wire protocol handling.

5 *

6 * Facebook Secret Conversations use Signal Protocol (X3DH + Double Ratchet)

7 * with their own framing on top. This module handles:

8 * - Key bundle upload/download to Facebook's graph endpoint

9 * - Message framing (encode/decode FCANX_E2EE frame format)

10 * - Signed pre-key signatures using HMAC-SHA256 (FB uses Ed25519 in practice;

package.jsonView file

•stage = ast_semantic_analysis; reason = ast_parse_error; limitedFiles = 1

High

Semantic Analysis Limited

A bounded semantic-analysis stage reached its safety limit; remaining detectors completed, but this package requires AI review.

package.jsonView on unpkg

src/api/socket/e2ee/e2ee/index.jsView file

•matchType = normalized_sha256 matchedPackage = shadowx-fca@10.6.0 matchedPath = src/api/socket/e2ee/e2ee/index.js matchedIdentity = npm:c2hhZG93eC1mY2E:10.6.0 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.

src/api/socket/e2ee/e2ee/index.jsView on unpkg

src/api/socket/e2ee/index.jsView file

•matchType = normalized_sha256 matchedPackage = shadowx-fca@10.6.0 matchedPath = src/api/socket/e2ee/index.js matchedIdentity = npm:c2hhZG93eC1mY2E:10.6.0 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.

src/api/socket/e2ee/index.jsView on unpkg

src/api/threads/getThreadInfo.jsView file

•matchType = normalized_sha256 matchedPackage = shadowx-fca@10.6.0 matchedPath = src/api/threads/getThreadInfo.js matchedIdentity = npm:c2hhZG93eC1mY2E:10.6.0 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.

src/api/threads/getThreadInfo.jsView on unpkg

src/api/users/getUserInfo.jsView file

•matchType = normalized_sha256 matchedPackage = shadowx-fca@10.6.0 matchedPath = src/api/users/getUserInfo.js matchedIdentity = npm:c2hhZG93eC1mY2E:10.6.0 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.

src/api/users/getUserInfo.jsView on unpkg

src/api/socket/core/getSeqID.jsView file

•matchType = previous_version_dangerous_delta matchedPackage = fca-nx@6.6.7 matchedIdentity = npm:ZmNhLW54:6.6.7 similarity = 0.942 summary = stored previous version shares package body but lacks this dangerous source file

High

Previous Version Dangerous Delta

This package version adds a dangerous source file absent from the previous stored version; route for source-aware review.

src/api/socket/core/getSeqID.jsView on unpkg

src/api/socket/e2ee/e2ee/vendor/fb-e2ee.cjsView file

Lines 2944-2984javascript

2944 "kyc-id",

2945 "privacy_token",

2946 "readreceipts",

2947 "appointment_only",

2948 "address",

2949 "expected_ts",

2950

src/api/socket/e2ee/vendor/fb-e2ee.cjsView file

2964patternName = google_api_key severity = high line = 2964

High

Secret Pattern

Google API key in src/api/socket/e2ee/vendor/fb-e2ee.cjs

src/api/socket/e2ee/vendor/fb-e2ee.cjsView on unpkg · L2964

Source & flagged code

15 flagged · loading source

e2ee/vendor/fb-e2ee.cjsView file

130copyProps(Buffer3, SafeBuffer); L131: SafeBuffer.from = function(arg, encodingOrOffset, length) { L132: if (typeof arg === "number") { ... L400: * @return {Object} Accepted configuration L401: * @private L402: */ ... L543: this._inflate[kWriteInProgress] = true; L544: this._inflate.write(data); L545: if (fin) this._inflate.write(TRAILER); ... L660: * @param {(String|Buffer|ArrayBuffer|Buffer[])} data The received data L661: * @param {WebSocket} target A reference to the target to which the event was dispatched L662: */

Critical

Hardcoded Runtime Data Exfiltration

Source sends credentials or rich application records to a package-controlled external receiver enabled by default.

e2ee/vendor/fb-e2ee.cjsView on unpkg · L130

2964patternName = google_api_key severity = high line = 2964

High

High Secret

Package contains a high-severity secret pattern.

e2ee/vendor/fb-e2ee.cjsView on unpkg · L2964

2964patternName = google_api_key severity = high line = 2964

High

Secret Pattern

Google API key in e2ee/vendor/fb-e2ee.cjs

e2ee/vendor/fb-e2ee.cjsView on unpkg · L2964

Findings

1 Critical11 High4 Medium6 Low

CriticalHardcoded Runtime Data Exfiltratione2ee/vendor/fb-e2ee.cjs

HighHigh Secrete2ee/vendor/fb-e2ee.cjs

HighSemantic Analysis Limitedpackage.json

HighKnown Malware Source Similaritye2ee/index.js

HighKnown Malware Source Similaritysrc/api/socket/e2ee/e2ee/index.js

HighKnown Malware Source Similaritysrc/api/socket/e2ee/index.js

HighKnown Malware Source Similaritysrc/api/threads/getThreadInfo.js

HighKnown Malware Source Similaritysrc/api/users/getUserInfo.js

HighPrevious Version Dangerous Deltasrc/api/socket/core/getSeqID.js

HighSecret Patterne2ee/vendor/fb-e2ee.cjs

HighSecret Pattern

Affected versions and remediation

This report applies to fca-nx@6.6.9.

See all versions of fca-nx for other recorded verdicts.

Review the evidence and your use of fca-nx@6.6.9 before allowing it. Restrict the permissions described in this report.
Choose an independently verified alternative or release. This report does not establish that other versions are safe.

Evidence last updated: 2026-09-11 21:36:49.474Z (UTC).

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

AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Runtime surface

Behavioral surface

Source & flagged code