Arkose FP Docs

This document contains some of my research on ArkoseLabs' FunCaptcha fingerprinting. This is missing a bunch of signals that I haven't got around to documenting since they're boring or self-explanatory. For example, hashes.

Hover over text with ⋯ below it to see more details.

View the DevTools console for more details (Ctrl+Shift+I).

See also:

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Table of Contents


    cfp

    Canvas fingerprint that's hashed using Java's hashCode method.

    WebGL

    Collects supported operations by your GPU via the WebGL API. This could, in theory, be used to correlate your canvas fingerprint as described in this paper by Google.

    audio_fingerprint

    See:

    1. How the Web Audio API is used for audio fingerprinting
    2. How We Bypassed Safari 17's Advanced Audio Fingerprinting Protection

    wh

    Window hash:

    1. Gets all the objects on the current window and sorts them.
    2. TODO: Prototype stuff.
    3. murmurHash3 both with a seed of 420.
    4. Join with "|".

    n

    Base64 encoded timestamp.

    window__tree_index

    These don't work in this environment.

    window__tree_structure

    TODO

    window__ancestor_origins

    TODO

    browser_object_checks

    • Checks for global objects belonging to different browsers.
    • Sorts them.
    • Joins them with ",".
    • md5 hashes them.

    See the console for more details.

    browser_detection_brave

    Detects the Brave browser via the brave global object.

    browser_detection_firefox

    Checks the User-Agent for "Firefox".

    navigator_pdf_viewer_enabled

    Checks: navigator.pdfViewerEnabled;

    user_agent_data_brands

    Checks: navigator.userAgentData.brands;

    user_agent_data_mobile

    Checks: navigator.userAgentData.mobile;

    screen_orientation

    Gets the current device screen orientation.

    fake_browser

    Checks for inconsistencies between the User-Agent and the behavior of the browser state.

    headless_browser_generic

    Checks the various objects on the document and window related to browser automation frameworks. Including:

    hasFakeOS

    Checks for inconsistencies with userAgent and platform.

    browser_api_checks

    Supported browser features

    navigator_permissions_hash

    • Checks which permissions the current page has.
    • Joins them with "|".
    • md5 hashes them.

    getPlugins

    Browser plugins.

    speech_default

    Text to speach information.

    For the hash:

    • Checks voices you have installed.
    • Joins them with ",".
    • md5 hashes them.

    navigator_battery_charging

    Checks: (await navigator.getBattery()).charging;

    media_devices

    Checks which media devices are available.

    getAudio

    Checks which audio codecs are available. This can be used to detect browser environments that don't support DRM.

    getVideo

    Checks which video codecs are available. This can be used to detect browser environments that don't support DRM.

    supported_math_functions

    Checks what Math functions are supported in the current browser.

    math_fingerprint

    Runs a bunch of math calculations.

    This can be used to detect if the enforcement script is being run in a different environment than is claimed by the client. For example, calculating the math like V8 (Chrome) but claiming to be JavaScriptCore (Safari).

    CDP Check

    Checks if you have DevTools open or are using Puppeteer.

    Sandbox Checks

    Checks for different sandbox environments such as JSDom.

    media_query_dark_mode

    Queries for dark mode.

    matchMedia("(prefers-color-scheme: dark)").matches;

    css_media_queries

    • matchMedia("(prefers-color-scheme:light)");
    • matchMedia("(prefers-color-scheme:dark)");

    css_color_gamut

    Checks what color gamuts are supported.

    • matchMedia("(color-gamut:rec2020)");
    • matchMedia("(color-gamut:p3)");
    • matchMedia("(color-gamut:srgb)");

    css_contrast

    Checks user's contrast preference.

    • matchMedia("(prefers-contrast:low)");
    • matchMedia("(prefers-contrast:less)");
    • matchMedia("(prefers-contrast:no-preference)");
    • matchMedia("(prefers-contrast:more)");
    • matchMedia("(prefers-contrast:high)");
    • matchMedia("(prefers-contrast:forced)");

    css_monochrome

    Checks user's monochrome preference.

    css_pointer

    • matchMedia("(any-pointer:1)");
    • matchMedia("(any-pointer:coarse)");
    • matchMedia("(any-pointer:none"); ")
    • matchMedia("(any-pointer:fine)");

    css_grid_support

    • matchMedia("(grid:1)");
    • matchMedia("(grid:0)");

    getFonts

    Checks for the presence of 65 different fonts from a predetermined list. This could be used to detect your platform. For example, Wingdings is only on Windows.

    TO

    Checks your timezone. This can be correlated with the approximate location of your IP address.

    rtc_peer_connection

    Checks the existence of:

    • window.RTCPeerConnection;
    • window.mozRTCPeerConnection;
    • window.webkitRTCPeerConnection;

    And then stores the result in a number using bit shifting.

    jsbd

    • HL: window.history.length;
    • NCE: navigator.cookieEnabled;
    • DT: document.title;
    • NWD: JSON.stringify(navigator.webdriver);

    6a62b2a558

    Script version hash:

    "enforcement.6c9d6e9be9aa044cc5ce9548b4abe1b0.js";

    4b4b269e68

    Random UUID:

    crypto.randomUUID();

    c8480e29a

    MD5 hashed surl.

    md5(surl) + (surl ? "\u2062" : "\u2063");

    4ca87df3d1

    mbio mouse events. See the events page for more details.

    function insertEvent() { const n = { timestamp: Date.now() - Qt.timestamp, type: e, x: m.pageX, y: m.pageY, }; Qt["4ca87df3d1"].push(n); _lastMouseMove = n; } if(Qt["4ca87df3d1"].length < 75) { if(e === 0) { if(_lastMouseMove) { if(Math.sqrt((m.pageX - _lastMouseMove.x) * (m.pageX - _lastMouseMove.x) + (m.pageY - _lastMouseMove.y) * (m.pageY - _lastMouseMove.y)) > 5) { insertEvent(); } return; } else { insertEvent(); return; } } Qt["4ca87df3d1"].push({ timestamp: Date.now() - Qt.timestamp, type: e, x: m.pageX, y: m.pageY, }); }

    867e25e5d4

    mbio touch events. See the events page for more details.

    for(let i = 0; i < v.touches.length; i += 1) { if(Qt["867e25e5d4"].length < 75) { Qt["867e25e5d4"].push({ timestamp: Date.now() - Qt.timestamp, type: e, x: Math.floor(v.touches[i].pageX), y: Math.floor(v.touches[i].pageY), }); } }

    d4a306884c

    mbio key events. See the events page for more details.

    const keyboardEventTypes = { Tab: 0, Enter: 1, Space: 3, ShiftLeft: 4, ShiftRight: 5, ControlLeft: 6, ControlRight: 7, MetaLeft: 8, MetaRight: 9, AltLeft: 10, AltRight: 11, Backspace: 12, Escape: 13, }; if(Qt.d4a306884c.length < 75) { Qt.d4a306884c.push({ timestamp: Date.now() - Qt.timestamp, type: e, code: keyboardEventTypes[A.code] ?? 14, }); }