Before opening any such file, it is highly recommended to scan it with an up-to-date antivirus.
: On Android, the official RAR app from Google Play is the standard.
: Proxy lists or "combo" lists (usernames and passwords) used to automate testing processes.
If you trust the source, you can use several tools to view the contents:
While the exact contents of this specific archive are not publicly documented in official libraries, files with this naming convention typically contain: