registry / Data exfiltration / @cyberdefenseinc/muypil

@cyberdefenseinc/muypil

Muypil™ - Tracker Javascript Library ========================

This report shows the evidence for @cyberdefenseinc/muypil@1.0.4. 1 of 2 known versions is blocked or flagged. The newest version, 1.0.5, is allowed. See all versions.

AI Security Review

scanned 2mo ago · by lpm-firewall-ai

The package contains a concealed browser surveillance payload that exfiltrates extensive fingerprint and interaction data to a remote host. Although it has no npm lifecycle hook, the loaded runtime behavior is concrete malicious data exfiltration.

Static reason

One or more suspicious static signals were detected.

Trigger

A browser loads tracker.js on a page whose URL includes __mp_ulid.

Impact

A remote operator receives detailed device and browser identifiers plus page and pointer activity, enabling cross-session tracking.

Mechanism

Obfuscated browser fingerprinting and event-data exfiltration via beacon or fetch.

Attack narrative

When included in a browser page, the obfuscated script reads a hidden URL parameter and installs page-load, unload, click, and pointer listeners. It compiles a broad fingerprint using browser APIs and sends serialized records to a remote Muypil API through sendBeacon or fetch. This substantially exceeds the stated interaction-tracking description and conceals collection through obfuscation.

AI rationale

Evidence

tracker.js

Network endpoints1

api-v1.muypil.com/tracker/path

Decision evidence

public snapshot

AI called this Malicious at 94.0% confidence as Malware with low false-positive risk.

Evidence for block

tracker.js is deliberately obfuscated, concealing its runtime behavior.
The browser payload automatically sends JSON with sendBeacon or fetch to api-v1.muypil.com.
It gathers extensive browser fingerprint, permission, battery, WebGL, audio, storage, and input-event data.
Activation is gated by a __mp_ulid URL parameter, then event listeners transmit page and pointer activity.

Evidence against

package.json has no install lifecycle hook or dependencies.
No filesystem writes, shell execution, credential-file access, or dynamic code execution were found.

Behavioral surface

SourceNo risky source behavior triggered.

Supply chain

MinifiedObfuscatedTrivial

ManifestNo manifest risk signals triggered.

scanned 1 file(s), 14.5 KB of source

Source & flagged code

7 flagged

tracker.jsView file

1const _0x335f8b=_0x1f99;function _0x1f99(_0x456f91,_0x99c651){const _0x4aaebc=_0x4f87();return _0x1f99=function(_0x3e0e69,_0x37b1e1){_0x3e0e69=_0x3e0e69-(-0x7*0x13d+-0x1*0xbb6+-0x1...

High

Obfuscated Payload Loader

Source contains an obfuscated payload loader that reconstructs and executes hidden code.

tracker.jsView on unpkg · L1

1const _0x335f8b=_0x1f99;function _0x1f99(_0x456f91,_0x99c651){const _0x4aaebc=_0x4f87();return _0x1f99=function(_0x3e0e69,_0x37b1e1){

High

Ai Review Evidence

tracker.js is deliberately obfuscated, concealing its runtime behavior.

tracker.jsView on unpkg · L1

1navigator[_0xb9753(0x1c3)]?navigator[_0xb9753(0x1c3)](''+_0x4be6af+this[_0xb9753(0x20d)],new Blob([JSON[_0xb9753(0x243)](this[_0xb9753(0x1aa)])],{'type':_0x4f1f41[_0xb9753(0x1a5)]}))

High

Ai Review Evidence

The browser payload automatically sends JSON with sendBeacon or fetch to api-v1.muypil.com.

tracker.jsView on unpkg · L1

1'permission','ECDwa','el_ratio','tiltY','event','baseLatenc','send','age','audio_outp','availWidth'

High

Ai Review Evidence

It gathers extensive browser fingerprint, permission, battery, WebGL, audio, storage, and input-event data.

tracker.jsView on unpkg · L1

1'WEBGL_debu','sendBeacon','feature_lo','cBLnE','battery_le','getContext','35xiuDRR','cal_storag','audio_base'

High

Ai Review Evidence

It gathers extensive browser fingerprint, permission, battery, WebGL, audio, storage, and input-event data.

tracker.jsView on unpkg · L1

1},_0xd2d1eb=new URL(window[_0x335f8b(0x15d)][_0x335f8b(0x1d0)])[_0x335f8b(0x1cd)+'ms'][_0x335f8b(0x19e)](_0x335f8b(0x222));

High

Ai Review Evidence

Activation is gated by a __mp_ulid URL parameter, then event listeners transmit page and pointer activity.

tracker.jsView on unpkg · L1

1if(_0xd2d1eb)_0x5f43be(_0xd2d1eb);

High

Ai Review Evidence

Activation is gated by a __mp_ulid URL parameter, then event listeners transmit page and pointer activity.

tracker.jsView on unpkg · L1

Source & flagged code

7 flagged · loading source

tracker.jsView file

1const _0x335f8b=_0x1f99;function _0x1f99(_0x456f91,_0x99c651){const _0x4aaebc=_0x4f87();return _0x1f99=function(_0x3e0e69,_0x37b1e1){_0x3e0e69=_0x3e0e69-(-0x7*0x13d+-0x1*0xbb6+-0x1...

High

Obfuscated Payload Loader

Source contains an obfuscated payload loader that reconstructs and executes hidden code.

tracker.jsView on unpkg · L1

1const _0x335f8b=_0x1f99;function _0x1f99(_0x456f91,_0x99c651){const _0x4aaebc=_0x4f87();return _0x1f99=function(_0x3e0e69,_0x37b1e1){

High

Ai Review Evidence

tracker.js is deliberately obfuscated, concealing its runtime behavior.

tracker.jsView on unpkg · L1

1navigator[_0xb9753(0x1c3)]?navigator[_0xb9753(0x1c3)](''+_0x4be6af+this[_0xb9753(0x20d)],new Blob([JSON[_0xb9753(0x243)](this[_0xb9753(0x1aa)])],{'type':_0x4f1f41[_0xb9753(0x1a5)]}))

High

Ai Review Evidence

The browser payload automatically sends JSON with sendBeacon or fetch to api-v1.muypil.com.

tracker.jsView on unpkg · L1

Findings

8 High1 Medium1 Low

HighObfuscated Payload Loadertracker.js

HighObfuscated

HighAi Review Evidencetracker.js

MediumStructural Risk Force Deep Review

LowScripts Present

Affected versions and remediation

This report applies to @cyberdefenseinc/muypil@1.0.4.

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

Avoid installing @cyberdefenseinc/muypil@1.0.4. 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: 2026-09-05 10:04:52.047Z (UTC).

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

Versions

2 known versions

1.0.5latestClean—AllowPublishedSep 25, 2026, 12:47 PM 1.0.4shownMaliciousData ExfiltrationBlockPublishedSep 3, 2026, 7:14 AM

AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Versions

Related packages

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Source & flagged code