Someone was kind enough to give me some information about a payment processor that VeryWell Casino, who is part of this shady bunch, uses. That was enough for me to find out a lot of information about it. The payment processor calls themselves WCR-Pay, and has a website at wallet-cointer dot com. They also have various other websites for processing payments at wallet-travel dot com, paynow-wallet dot com, pepwallet dot net, qwallety dot net, and piastrix dot com (and piastrix dot ru). Piastrix is also used by a binary option website, and binary option websites are infamous for being scams.
One of the websites say they are ran by "Cointer Sp. z o.o.", and that may be true for some of the websites, but in the past they were likely ran by "Prominer Sp. z o.o.", which has a website at prominer dot pl and which was founded in 2018 - and both companies are registered in Poland. Prominer boasts on their website of being "a young dynamically developing team specializing in creating software for payment systems", and has an active payment processor website at first-icard dot com. Both of the names of the people who run the companies in question are Ukrainian from what I can tell, and it would be my bet that they're working together.