Did you sign up with`this company or did they just contact you out of the blue? If you signed up with them, how did you find them? When a company sends you a check or contacts you with a mystery shopping job when you have not signed up with them, they are probably not legit. A legitimate company requires you to sign up, provide your SS# and personal information, and sign a confidentiality agreement before they assign you any jobs. Most legitimate companies require that you do the work before they send you money. Receiving a check to deposit is a total red flag.