The Dropbox desktop client uses lightweight integrations with the Windows and MacOS operating systems to function. These integrations are called drivers (on Windows) and kernel extensions (on MacOS), and they allow Dropbox to receive notice of file and folder actions and sync them.
Use of the kernel extensions and minifilter drivers is common among many popular systems:
Select your operating system to learn more about kernel extension or minifilter driver on your specific computer.
Dropbox used publicly-available APIs from Apple and Microsoft to write the kernel extension and minifilter driver. No additional admin permissions are required (beyond what Dropbox has always needed to function).
Kernel extensions enable "callbacks." Callbacks are real-time calls that confirm you have permission to do things like move, delete, or change ownership of content in shared spaces. If you don’t have these file access permissions, kernel extensions allow Dropbox to send warnings when you may be taking an action that could unshare folders or delete shared content.
Kernel extensions and minifilter drivers can give applications additional access to your computer’s operating system. Dropbox is cautious in only using these extensions to improve your experience with our app.
Some notes on what we do not do:
Dropbox takes great measures to protect your data and privacy, and we designed the minifilter driver and kernel extension with security and stability as top priorities. In fact, many of the engineers who wrote this extension previously worked on filesystem technologies at various OS vendors.
These components have gone through extensive security reviews with internal security teams, as well as audits done by external penetration testers. We’ve run these components both internally at Dropbox and in cooperation with enterprise-scale beta customers. In both cases these components ran successfully.
These integrations are core to current and future Dropbox client services. There is no way to disable or opt-out of using the minifilter driver or kernel extension on the Dropbox desktop client. Doing so would also disable important alerts that prevent users from accidentally deleting shared data, or taking unintended file actions.
If you don’t want to install the Dropbox desktop application, you can view, share, and download your files without the desktop integration by using only the Dropbox website at dropbox.com.