A file named is a compressed archive created using the RAR (Roshal Archive) format. The name suggests it is the fourth copy or iteration of a "New" folder or file, often resulting from multiple downloads or "Save As" actions in the same directory. Overview of RAR4 vs. RAR5

Because the file extension is .rar , it could be based on either the older or the modern RAR5 standard.

Since Windows and macOS do not always provide full native support for RAR files, you typically need third-party software to view or extract the contents. Find out what's new with WinRAR

: Uses AES-128 encryption and an XOR-based recovery record.

: The current standard since WinRAR 5.0, offering stronger AES-256 encryption , better recovery through Reed-Solomon error correction, and support for massive dictionary sizes (up to 1 GB) for better compression. How to Access Content in New(4).rar