You can install the free Zscaler Likejacking Prevention tool for Firefox, Google Chrome and Safari. The extension offer 2 primary features:
- Information about the page: does it contain Facebook widgets? Are these widgets hidden?
- Protection against hidden widgets: the application requires explicit confirmation from the user when clicking on a Facebook widgets on a suspicious page
On Firefox and Chrome, an icon is displayed in the URL bar when a page contains at least one Facebook widget. If the page is suspicious, meaning hidden widgets were detected, the icon has a red background. You can use http://www.zscaler.com/research/plugins/likejacking/example.htm as an example of a suspicious page.
|Suspicious page found in Firefox|
|Safe page found in Chrome|
|Suspicious page found in Safari|
You can obtain more information on the page -- either by clicking on the icon, or "More options" in Safari -- including:
- how many widgets were found on the page
- whether the page is suspicious or not
- what protection was applied on the Facebook widgets
|Information, and actions, for a page with Facebook widgets (Chrome)|
You can also report back to Zscaler, any page that was classified improperly by clicking on "Report an error". This will open a new tab in your browser and send you to a form on the zscaler.com website. We will use this information to improve the add-on.
Display hidden widgets
As you can see in the Youtube video, it is possible to expose the hidden widgets. The extension can modify the source of the page (opacity, height, weight, z-index, overflow, etc.). You can try this feature on http://www.zscaler.com/research/plugins/likejacking/example.htm.
|Hidden Like buttons exposed in Firefox|
You can choose your level of protection in the preferences:
- Delete all Facebook widgets - Choose this option if you never use "Like" buttons on external sites. You can always whitelist a domain to keep the widgets on a particular site.
- Always ask for explicit confirmation - A popup will warn you that you clicked on an element that is trying to post to your public profile. You can decide to stop the action, or to let the page post to your profile. This is a good option if your rarely click on "Like" buttons.
- Ask for explicit confirmation only on suspicious pages with hidden widgets - This is a good balance between security and productivity. It is the recommended setting.
|Explicit confirmation in Safari|
|Extension preferences in Chrome|
The extension does not affect the ability to use the main Facebook site; it protects users only on other sites that use widgets from Facebook.
Some Facebook widgets are hidden by design. This is normal, and the the extension will not list them as suspicious and will not apply any protection on those.
I will post another blog on the process of creating the plugin for different browsers to explain the challenges I faced on each platform.