It's called a "Check Overpayment Fraud". The fraud artist claims to want to rent or buy something, then tries to con the seller into accepting a forged money order, forged certified check or stolen credit card. Frequently the check amount is for more than the selling or rental price, and the scammers asks that the balance be sent to a 3rd party. Another variation is that the fraud artist sends a "deposit", then later claims to be unable to complete the deal, so asks for a refund.
Because I'm in the vacation rental business, I see it for vacation rentals, but there's a similar scam targeted at people selling vehicles, and there are probably other variations targeted at anyone trying to sell or rent anything of high monetary value.
See: http://netforbeginners.about.com/od/scamsandidentitytheft/ss/top10inetscams_5.htm for more details.
The "overpayment" is usually (but not always) a relatively small amount to supposedly to cover the expenses of someone who is already in travel. For example sometimes they claim to be a female model, or a minister, or an oil company rep, etc. and they're already in some other city in the country and need money for travel and living expenses until they arrive at the vacation rental, or they need to pay for a 3rd party to transport the vehicle to elsewhere, etc.
Since the vacation rental has yet to be occupied, or the vehicle has yet to leave the driveway, some owners may feel secure is sending the relatively small over payment to the 3rd party.
The owner's bank will often accept these payments for deposit, but needless to say whatever payment used, it eventually bounces, and bank comes back to the customer for repayment, so the property owner is out whatever amount they are foolish enough to sent to the 3rd party. That can sometimes be hundreds even thousands of dollars!
The Deposit/Refund Version is another variation. In this scam, the fraud artist will make a large deposit for an item (several weeks rental or a vehicle) using a forged money order, forged certified check or stolen credit card. As soon as the check has been cashed, (but not yet cleared the banking system) he will come up with some hard luck story of why he is unable to complete the transaction, and ask for a refund of all or part of the deposit.
Anyone gullible enough refund the deposit before the check/money order fully clears gets caught!
In this scam, they claim to a company in need of a "Payment Officer" to "establish a medium of getting to our customers in America/Canada as well as making payments". They offer a "commission of 10% of whatever amount of payment you receive from customers on behalf of the company".
Needless to say, the payments will be by forged money order, forged certified check or stolen credit card.
As I said, I see these several times a week. They're usually easy to spot.
Most of the time these scams are so poorly done that no one falls for them. They're usually poorly written, vague about where your property is located for example "in your country", and vague about what type of accommodations it is (i.e.. apt, house, etc.). Very often they seem unusually anxious to pay. Often they claim to be ministers, doctors, female models, artists, and oil company employees. Scammers running the deposit/refund scam tend to ask a lot of questions about refund policies.
As I indicated above, most of these scams are crude and easy to spot, but even so I do know of a case where the con artist was skilled enough to cause one of my customers major problems. It got to the point where she received the check and went to deposit it at her bank. The bank immediately recognized the check as a forgery and called the police, who then detained my customer for a brief period while they checked out her story. No money was lost, but there was certainly embarrassment and inconvenience, and a great story the tell the grandchildren about the time Grandma was arrested for forgery!
The simple principle is to very careful about accepting certified checks or money orders. The vast majority of the checks are legitimate, but its next to impossible to tell by looking at them. If there's any doubt about a check ask your bank about it and ask how long it will take to clear the banking system. Do not provide refunds until the check has fully cleared, and never accept checks for greater than the amount due, yet alone send "the change" to someone.
These people never intend to arrive at your vacation property, so certified checks for the correct amount from actual customers who do arrive at your vacation rental are not the problem.
When I get them, I forward them to the "Abuse" account of fraud artist's email provider (usually abuse@Yahoo.com, report_spam@Hotmail.com, or abuse@MSN.com). I have a standard message to the email provider in which I explain the fraud and ask them to delete the fraud artist's email account(s). The email providers are always happy to do so. That way, the scammer loses any replies he might receive.
I have had customers expressing opinions that I should do something more about it, but to be quite honest I simply don't have the resources to do anything else. What I told people was: "If you had an ad in the classified ad section of your local newspaper and encountered such a fraud, would you demand that the newspaper do something about it, other than publishing the information?". So far all have agreed that it would not be a reasonable demand.
This is criminal activity, so perhaps we should be demanding that law enforcement agencies do something about it. I realize that it's next to impossible to get international cooperation to prosecute frauds of a few hundred dollars, but the actual tracking down of these people would be quite easy. Maybe if enough people complained to their law enforcement agencies they might get together to do something.
Other than that, there's not much anyone can do, except to be cautious.