Could you share or what the email/website claimed it was? This will help me give you a much more specific breakdown.

Filenames consisting of 5-digit strings (like 52869) are frequently used by Trojan droppers or phishing campaigns. These files often arrive as email attachments disguised as "Invoices" or "Shipping Documents."

This format supports AES-256 encryption. if you try to open it and it asks for a password, the data is encrypted. Safety Recommendations

Some niche drivers or firmware updates for legacy hardware use numerical identifiers corresponding to a specific version or build number in a developer's database. Technical Characteristics of .RAR Files