Google has announced that when Google Chrome 25 for Windows arrives, attempts by third party applications to silently install extensions will now trigger a dialog window to be displayed and, until the user confirms the extension is legitimate, the extension will remain disabled. The company says the technique, known as sideloading extensions, was originally designed to make it easier for applications to add appropriate extensions to Chrome by modifying the registry when being installed.

The feature has, however, been "widely abused by third parties" say the company. The abuse of the extension or add-on system is nothing new; over a year ago Firefox 8 introduced similar features that slowed the install of add-ons, Mozilla's version of extensions. Another change in Chrome 25 which is similar to Firefox's solution is the disabling of all previously installed third-party extensions. The idea behind this change is to ensure that users audit their installed extensions and are aware of what has already been added to their browser's configuration.

Google recommends that Windows developers use their inline installation mechanism for adding extensions in the future. This allows extensions to be served from Google's Chrome Web Store in the background while appearing to be installed from the extension developer's web site.