Don't get taken by the mystery shopper scam
You'll notice right away that the fraud relies on companies and logos you are familiar with to gain your trust. Who hasn't heard of Experian? Look there's even a Better Business Bureau logo claiming it is an accredited business. On top of these logos, the trust shown by sending along a $4,000 check is often enough to trick people into falling for the scam.
It's important to remember that legitimate mystery shopping companies will never charge you to become a mystery shopper or send you $4,000 as part of a program you didn't sign up for. The next time you need to send money via a wire transfer, read these questions from Western Union, particularly the two about not sending money to people you don't know and to be cautious about deals that seem too good to be true. Even with advanced security measures, the best tool against this type of scam is, as always, education.