Experts warn against malware that can drain accounts of ATM users in Mexico

HOUSTON (KTRK) -- A security firm is uncovering a hack in ATMs south of the border and it could make its way to the U.S.

There are two ATM hacks to be worried about: One will drain the ATM of money; the other will drain cash from your bank account.

You probably know the internal computers of ATMs are under lock and key, but you may not know the many of the locks can be opened by a single master key. Hackers in Mexico apparently have copies of that key and are programming the computers to steal your money.

"That's a little scary," ATM user Ellen Embry said.

Cyber security firms have found two types of malware on ATMs South of the border. One type seizes your card once you enter the passcode. Only the hackers can remove the card and armed with the PIN, they can withdrawal all your cash.

"If the people are freaking out because it is holding their card, hit cancel; and if does not spit it out, jerk it out of there because there is something wrong, that malware has done something to that lock on that card reader," ATM consultant Chris Tipton said.

Tipton knows how keep hackers out of his ATMs.

"We changed all our locks," he said.

The other malware causes the ATM to dispense all its cash on command. While the malware is not in the U.S., industry officials say the code found in Mexico could be used in America, if the machines are not adequately protected.

"Unless they have our keys, they can't get into the top of the machines," Tipton said.

For travelers, the best advice is pretty simple, if you must use the ATM, only do so at banks or hotels, and if you can, use your credit card, rather than the ATM feature if you are not at a trusted location.