This miner seems to have also "stolen" the code for Swap from the SwapRefMiner (an open source fork of grin-miner). It's still sending "SwapRefMiner/1.0.2" as the agent when connecting
{"jsonrpc":"2.0","method":"login","id":"Stratum","params":{"login":"","pass":"x","agent":"SwapRefMiner/1.0.2"}}
if true, you need to make your fee 0% or else you're just a thief.