(CBS) -- If you're buying or selling a house, you need to know about a growing scam that could derail your deal and steal your money.
This cyber-crime has gotten so big the National Association of Realtors has issued a fraud alert about it.
Now Debbie Groover wants to warn others about how she almost lost $831,000 she recently paid for a Lake Shore Drive condo.
"I was freaking out," Groover said after she realized her mistake. "I was choking back tears. I was terrified. Huge amount of money. I could not recover from something like this."
Groover added, "It's crazy. I can't believe what they are doing. And I can't believe how easy it was for them to do it."
So easy that Jessica Edgerton, Associate Council with National Association of Realtors, has issued a fraud alert warning about it.
"In recent months there really has been an upswing in this particularly insidious scam," Edgerton said.
"These are very sophisticated criminals."
Here's how she says they do it. Cyber criminals access emails sent from free Wi-Fi locations or through unsecured free email accounts.
"They will specifically target people in the real estate industry and so that way they can skulk in the background," Edgerton said, "Watching all the information go back and forth."
When it's time to wire the money the fraudsters will create an email address very similar to someone involved in the negotiations like the attorneys or realtors. The message will go something like this, Edgerton said.
"Say hey there's been a last minute change, the new banking and wiring instructions. Congratulations everybody."
Then it will instruct the buyer to send the money to an account the fraudster has control over.
Groover got wiring instructions from an email address very similar to the seller's attorney.
"Really it was the hackers," Edgerton said.
When she realized that, "I stood up and said, 'Oh my God this is a scam.'"
Her boyfriend Chip Gore, a software sales engineer, was able to use his computer skills to figure out where the fraudulent email originated from.
"That proves to be a machine that was located in Prague Czechoslovakia," Gore said.
Groover acted fast, and within hours was able to freeze the transfer of the money. If she hadn't, "I never would have seen that money again."
Most people are not so fortunate. Edgerton says buyers could lose down payments of $10,000 or $50,000 in some cases. The worst reported loss the Realtors Association has heard about was half a million dollars wired to a fraudsters account.
Edgerton said, "The money actually gets sent to a bank account that is cleared out and the person disappears in the ether forever."
To protect yourself from getting scammed Edgerton says you should not trust wiring instructions that come in an email. Before sending the money call the seller, the broker, the attorneys, or title company to verify where the money should be sent.
And since the scammers will send you a fake phone number that belongs to them, make sure you are calling the correct number for those people. Otherwise you will be talking to the fraudster and he will verify that the wrong wiring instructions are actually correct.
Finally, if the wire includes the words "swift wire" – that's a clue your money is being mailed overseas.
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