Malware researchers – here’s how to download a browser extension without installing it.

Downloading a browser extension without immediately installing it can be useful for offline installation, security analysis, or archival purposes. While most users add extensions directly through their browser’s web store, there are several professional methods to obtain the extension package file—typically a .crx file for Chrome and Edge—without triggering installation. Below, we outline the most effective approaches.

Use a Web-Based CRX Downloader

There are reputable online tools that allow users to download the .crx installation file for any Chrome or Edge extension. By entering the extension’s Web Store URL or unique ID, these services generate a direct download link for the extension package. This method is straightforward and does not require installing additional software although most are bloated with ads.

Utilize a Dedicated Browser Extension or Tool

Some browser extensions, such as Get CRX, add a “Get CRX” button to the Chrome Web Store interface, allowing users to download the .crx file directly from the extension’s listing. For advanced users, command-line tools like extension-downloader (available on GitHub) can fetch extension files by specifying the extension ID in a configuration file.

Manually Pack an Installed Extension

If the extension is already installed in your browser, you can manually create a .crx package:

• Navigate to the extension’s folder on your computer (commonly found under C:\Users\<YourName>\AppData\Local\Google\Chrome\User Data\Default\Extensions\ on Windows).
• Use Chrome’s “Pack extension” feature in Developer Mode to generate a .crx file.
  This approach is particularly useful if the extension is no longer available in the web store.

Download Directly from the Developer

Some developers provide the extension’s .crx file or a zipped version on their official websites, often linked from the Chrome Web Store listing. This is the most direct and secure way to obtain the official package, provided you trust the source.

Command-Line Tools for Advanced Users

For those comfortable with the command line, tools like extension-downloader allow batch downloading of extension files for Chrome, Edge, or Firefox. These tools typically require you to specify the extension IDs and output location.

Important Considerations

• Downloaded .crx files can be installed manually by dragging and dropping them onto the chrome://extensions page with Developer Mode enabled.
• For security reasons, Chrome and Edge may restrict installation of extensions not sourced from their official stores.
• Always verify the source and integrity of any extension before installation to avoid potential security risks.