SAN DIEGO -- Experts said it is a crime of greed.

Scammers lure their victims into a scheme, in this case, with an ad on the Craigslist Web site.

The offer? To make fast money while working from home.

Special Agent Bob Heyer of the Secret Service warns these schemes are difficult cases. It’s tough to find the culprits and they often operate out of countries with no extradition treaties with the United States.

"The victim, unfortunately, is not only going to become a victim of the crime, but of their own greed as well," said Heyer.

The crime being committed is a new twist on fraud using counterfeit Wal-Mart money orders.

The 10News investigations team obtained e-mails showing correspondence between a victim and a man identified as Harold Fox working for an online furniture company.

In this particular scheme, the victim would work from home as an administrative assistant, experts said. All they would do is receive money orders from furniture sales, deposit them in their own bank and then wire funds from their account to the vendors. The assistant keeps a percentage and is encouraged to complete the transaction quickly.

"That's the key because the criminal is trying to shortcut the standard business cycle," said Heyer.

Within days of answering the ad, the victim received a UPS package with $2,700 Wal-Mart money orders from a John Lurie in Sebring, Fla.

The victim's take from the transaction would have been about $300, except all three of the money orders were fake.

Placed side-by-side with a legitimate money order, many cannot tell the difference -- except for two things.

The back of the real money order has an 800 number, while the fraudulent has no 800 number.

Also, on the front of the real Wal-Mart money order, a watermark will disappear and slowly reappear when rubbed.

On the front of the fraudulent money order, nothing happens when the watermark is rubbed.

10News' research team traced the address on the UPS package from Lurie to a location in Florida that turns out to be a county administration building.

No private business suites were there, and there was no trace of Lurie.

"No John Lurie. They (Florida authorities) were aware of this particular case. They had received 5 or 6 calls in regards to that, all happening in a span of a couple of weeks," said I-Team researcher Andrew Madarang.

The Secret Service told 10News these cases rarely lead anywhere and they are hard to prosecute because those involved are overseas and live in countries with no extradition laws.

The Secret Service said the Wal-Mart money order scam is not the first of its kind and probably won't be the last. They said if it seems too good to be true, it probably is, so people should stay away.