If you’re in the process of buying a home, or plan to be, you need to be aware of real estate wire fraud.

The goal of this scam is to convince the victim to move the money for a down payment—usually tens, if not hundreds, of thousands of dollars—into an account controlled by the scammer, via wire transfer. And the problem with money sent by wire transfer is that it’s effectively impossible to retrieve. You could lose your down payment and the house.

In some cases, the thieves will use phishing techniques or malicious software to gain access to a realtor’s email accounts, then monitor communications for pending sales. In others, they may use publicly available online tools to identify pending sales, then set up a fake email account that will appear to come from the actual realtor (if the victim doesn’t examine it too closely).

When a sale is approaching its closing date, the thief will send an urgent email to the victim informing them that the instructions for making the down payment have changed—either a check is no longer acceptable and the victim will have to wire the funds, or if the payment was originally going to be made via wire, that they need it to be sent to a different account.

Either way, the message will include wiring instructions that lead to an account held by the scammer, not the realtor.

Losses from real estate wire fraud are growing, with hundreds of millions lost (and that number may be far lower than the actual total—many cases go unreported due to the potential for reputation damage). If you’re buying a house, know that you may very well be targeted. If you receive any new wiring information via email, or a message instructing you to e-sign documents or log in to a website, verify that with a call to the realtor to make sure it’s legit. Double-check everything in that email—is it coming from the correct email address; has the realtor’s command of English grammar suddenly changed?—and slow down instead of reacting quickly in the moment.

Going through extra steps can be a pain, but nothing compared to the pain of sending your entire down payment to a criminal.