LOUISVILLE, KY (WAVE) – Key information was lifted from every single Target store in the United States after 40 million credit and debit card numbers were stolen from a retail giant.
The act was a highly sophisticated crime and some experts question if it could be an inside job.
Despite the massive security breach, Megan Wesley returned to the Clarksville Target after making sure she wasn't victimized.
"I got online and checked my statement right away because we had shopped here to make sure there was nothing weird on there and there wasn't," said Wesley.
Some shoppers said just to be safe they decided to use cash. Target said the problem started on Black Friday, but wasn't detected until last Sunday.
But how could something like this happen? Michael Losavio, a computer engineering and science professor at the University of Louisville said the information is encrypted and only a limited number of people would have access to it.
"People speculate that maybe someone was able to get into their main systems and bypass all of that. Other speculations are through some method they were able to distribute trojan software to all of the card readers in all of the stores," said Losavio.
In 17 days, 40 million credit and debit cards were exposed. "They are probably only going to target a small number of those, but that still leaves your information out in the wild subject to compromise later on," said Losavio.
Republic Bank made to decision to go ahead and issue new cards to all their customers who shopped at Target during that time, but if you decide not to cancel your account keep a close eye on it.
"If you see any unusual or unauthorized activity please contact the bank right away," said Ann Bauer, Republic Bank Vice President.
Target said the problem has been fixed. The Secret Service will continue to investigate to try to get to the bottom of it.