.ARN File Extension
What is an ARN file?
Native Autoruns binary file format used to display everything that runs automatically when Windows starts; contains all the captured data results; does not include omitted rows.
The ARN file format can be loaded in Autoruns for viewing and comparing with another set of Autoruns results. The ARN file stores data in a binary format whereas the .TXT file stores Autoruns data in text format.
Autoruns is a utility used to show you what programs are configured to run during a system boot up. Some of the programs include Run, RunOnce, and startup folder.