using a service like VirusTotal before opening.

: Often, specific builds or version iterations use these alphanumeric strings.

If you received this file from an untrusted source, be cautious. .rar files with obscure alphanumeric names are frequently used to deliver or ransomware . Do not extract the file if you are unsure of its origin.

If you can provide more context, I can help you "reverse engineer" what might be inside. For example: Where did you ?