A browser extension that allows you to monitor, intercept, and debug JavaScript sinks based on customizable configurations.

📦 Installation

From extension stores:

• Firefox: https://addons.mozilla.org/en-US/firefox/addon/domloggerpp
• Chromium: https://chrome.google.com/webstore/detail/domlogger%2B%2B/lkpfjhmpbmpflldmdpdoabimdbaclolp
• Safari: Not yet available.

Manual installation:

Download the latest release: https://github.com/kevin-mizu/domloggerpp/releases/

• Firefox: Go to about:debugging#/runtime/this-firefox and click on Load Temporary Add-on.

• Chromium: Go to chrome://extensions/, enable Developer mode and click on Load unpacked.

if you want to build the extension by yourself, check the app folder.

🌟 Features

• Regex-based domain management.
• Flexible hooking configuration (class, function, attribute, event).
• Regex-based hooks arguments filtering (match, !match).
• Dynamic sinks arguments update (hookFunction).
• Customizable notifications system (alert, notification).
• On-demand debugging breakpoints.
• Integrated Devtools log panel.
• Remote logging via webhooks.
• Extensive theme customization.

📝 Usage example

usage.mp4

🛠️ Devtools

1. Custom filter buttons: Dynamically generated from your custom settings, these buttons facilitate log filtering.
2. Data/Canary search bar: Easily filter and highlight logs using specific criteria related to a sink's args data.
3. Advanced column search: Tailor your search to specific column criteria, like sink=innerHTML;frame=top, for more refined results.
4. Global search bar: This default datatable feature enables searching across all columns.
5. Debug button: Navigate directly to the page triggering the sink, with an automatic breakpoint for debugging.
6. Log data management buttons:
   • Import JSON log data.
   • Clear existing log data.
   • Export log data in JSON format.

💬 Popup

• Domains: Define allowed domains using regex to specify from which sites you'd like to receive logs.
• Hooking: Choose the hooking configuration to apply on the selected website.

⚙️ Settings

settings.mp4

• Settings: Manage your hooking configurations - create, edit, modify, and remove as per your needs.
• Domains: Easily manage allowed domains, similar to the functionality in the popup menu.
• Webhook: Specify a remote host that will receive logs based on your configuration settings.
• Devtools: If you're using a backend server and prefer not to display information in your devtool panel, this section lets you disable that feature.
• Table: Personalize the devtools tables to align with your preferences.
• Customize: Personalize the application's theme to align with your preferences.

🔗 Hooking configuration

Global JSON structure

{
    "_description": "JSON config example",

    "hooks": {
        "category": {
            "type_1": [ "sink_1", "sink_2" ],
            "type_2": [ "sink_1", "sink_2" ]
        }
    },

    "config": {
        "*": {},
        "sink_1": {
            "match": [ "regex_1", "regex_2", "exec:return 'regex_3'" ],
            "!match": [ "regex_1", "regex_2", "exec:return 'regex_3'" ],
            "hookFunction": "return args",
            "alert": {
                "match": [ "regex_1", "regex_2", "exec:return 'regex_3'" ],
                "!match": [ "regex_1", "regex_2", "exec:return 'regex_3'" ],
                "notification": true
            }
        }
    },

    "removeHeaders": [ "content-security-policy" ]
}

None of the specified keys in the configuration are mandatory; they can be manage to fit specific needs or omitted as desired.

_Description

This key aims to provide a way to insert notes within the configuration JSON itself. The value can be whatever you want as long as the JSON remains valid.

Hooks

• category: Acts as a filter in the devtools panel, helping you organize and identify the sinks.
• type_X: Specifies the type of sink you're targeting. The possible types are:
  • class
  • attribute
  • function
  • event
  • custom
• sink_X: This denotes the name of the sink that needs to be hooked, the notation varies based on type:
  • class & function: Use the target name directly, such as URLSearchParams.
  • event: Only use the event name. For instance, for the onmessage event, simply use message.
  • attribute: Prefix with set: or/and get: as appropriate. An example would be set:Element.prototype.innerHTML.
  • custom: Format it as type:sink_X. For example, attribute:set:jQuery.prototype.add.

Config

• sink: Refers to the target sink to be configured. It's essential for this to be present in the hooks section.
• match: An array of regular expressions. The parameters of the sink must respect to these patterns.
• !match: An array of regular expressions that the parameters of the sink should not match.
• hookFunction: This function takes the sink's arguments and allows you to modify them before the original function is invoked. For example, using return [args[0] + '*2'] on eval('2') will result in 4.
• alert: Triggers an alert badge on the extension icon based on specific conditions.
  • match & !match: Additional regular expressions that the sink parameters must respect to or avoid, respectively, in order to trigger the alert.
  • notification: If set to true, a notification popup will appear when all conditions are satisfied.

Since version 1.0.4, it is now possible to use the exec: regex directive, which allows you to generate a regex from JavaScript execution. For instance: exec:return document.location.pathname.

For more detailed examples and insights, please refer to the configs folder.

removeHeaders

Thanks to this key, you'll be able to provide a list of response headers (in lower case) that you want to remove if the remove headers feature is enabled. This is especially useful for removing security headers during tests.

🖥️ Backend

Not yet developed.

🗺️ Road map

• Set up an integrated backend server.
• Improve the scaling of the devtools panel.
• Find a way to log Content Security Policy (CSP) errors.
• Find a way to hook the document.location property.
• Simplify headless browser compatibility.
• Fix a DOS with Reflect.apply, crypto, this.nodeName.toLowerCase... hooking.
• Fix the devtools goto button when the sink is reached within an iframe (it should redirect on the top frame).

🤝 Contributors

Many people helped and help DOMLogger++ become what it is and need to be acknowledged here!

@aituglo, @xnl_h4ck3r, AetherBlack, @FeelProud_sec, aristosMiliaressis, @me0wday, @k1ng_pr4wn

Special thanks to @BitK_ for the well-structured code in Pwnfox, it helped me a lot to understand browsers extensions ❤️