This is often the format for files found on file-sharing sites, Usenet, or forums. The "WEB4K" suggests it might be a 4K resolution video sourced from a web streaming platform.
It could be part of an encrypted or segmented corporate backup or data export. BKAD22WEB4K9.part4.rar
Because this name is so specific, it could refer to a few different things: This is often the format for files found