So... Did you mine anything and were you able to withdraw?

I reckon this is just a typical mining pyramid scheme trying to sucker a few into buying contacts which then pay for the limited free contacts.

Or they are just after emails of people who use crypto currency so they can target them for hacking. Once they have your payout address they may also be able to discover other stuff about you by following the blockchain. And they may end up putting spyware or malware on their site to catch the unpatched.

Let's just say I don't trust random Russian sites and neither should anyone.