Anyone knows about those guys ?
cryptoextraction.com
Seems like a scam to me. It further makes more suspicious since they are claiming
"their clients made 189% profit in 2019" and their whois data shows site registered in Jan 2018. My advice- stay away.
Also maybe negative highlights from here will help you understand about the site better:
https://www.scamadviser.com/is-cryptoextraction.com-a-fake-site.html