Maine banks and credit unions have alerted authorities of the rising number of customers they've seen attempting to cash fraudulent checks from the mail.

It may not come as a huge surprise that you probably shouldn't trust a check sent to you from someone you don't know and didn't render any services to, but it's easy to find yourself falling for the unlikely, especially if you haven't told to be suspicious.

That's how scams work, after all!

The latest scam spreading through Maine is a unique one, WABI reports. Under the guise of an "undercover shopper," targets receive instructions in the mail to deposit a certain amount of money, then use it to buy gift cards from select stores in order to "evaluate" the service, according to the news station. Targets are then told to send the purchased gift cards to a designated address in order to keep some of the cash.

Jen Burke of the Maine Credit Union League put it perfectly in her advice to WABI:

"If someone receives a letter in the mail with free money, free cash, if it seems to good to be true, chances are it is."