Is there an ANN thread in bitcointalk.org or the official grin forum?
because I feel uneasy of trusting them without any user comments.
Could be a virus chest.
Well I haven't found one, but I think that GrinPro's team is related to Ace miner:
https://bitcointalk.org/index.php?topic=5097693.0Both miners passed my security check, but that doesn't really say much.