How can I find out which affiliate network an offer is from

I'm in the affiliate industry. How can I find out which affiliate network an offer is from? I recently found an offer I'm interested in, but I noticed the redirect URL has a sub_aff=XXXX parameter. This suggests the offer is being sourced from another network. I've managed to find the original network's offer ID and domain, but I can't find any related information on sites like Affplus or Overvault. Are there any other methods I can use?

Or is it possible that this is a first-party offer, and the advertiser just uses different categories for various