It became known that the Mozilla company started using a new method of identifying installations of its Firefox browser. According to the available data, dltoken identifiers, unique for each download, are integrated into Firefox exe files for the Windows operating system distributed through the developers’ official website.
This means that multiple consecutive downloads of an installation archive for the same platform will result in downloads of files with different checksums, since the identifiers are built right into the installation file itself. At the same time, downloading the installer through a browser or command line on Linux always downloads the same exe files. The browser archive, which does not contain any executable files, remains unchanged even after multiple downloads.
According to available data, you can disable dltoken billing by disabling telemetry in browser settings. This option is not suitable for initial installation, since changing telemetry settings in the browser itself does not affect data replacement on the server when data is loaded from the website for the first time.
According to reports, you can get a Firefox installer file without an ID by downloading it directly from ftp.mozilla.org. Perhaps the integration of identifiers in .exe files is due to developers’ desire to associate initial installs with telemetry and Google Analytics identifiers with actual application downloads. By collecting this data, you can identify the root causes of discrepancies in downloads and installs to understand which installs are caused by which downloads.