Hundreds of people in Arizona have spent hours on the phone with the bank trying to get bogus charges off of their credit and debit cards.
It's unknown how many credit card numbers were stolen from folks who shop at three Valley grocery stores.
Bashas' spokeswoman Kristy Jozwiak told CBS 5 the security breech affects customers who have shopped at Bashas', AJ's and Food City Stores. [Related: FBI investigating cyber attack on Bashas' customers]
Pinal County Sheriff Paul Babeu said the company has known about the problem for a long time. However, Jozwiak said that's absolutely not true.
"This is very recent," Jozwiak said. "We just started fielding calls from customers. We immediately started looking into the situation and very recently as of yesterday morning located that malware on our system. We identified it, we contained it and we removed it."
Within hours of finding out about the problem, Jozwiak said stores posted signs warning customers at registers and online.
The Bashas' spokeswoman added forensic experts told her whatever malicious software was used to hack into the system is something they've never seen before.
Data Doctors computer expert Ken Colburn told CBS 5 that's entirely possible.
"It could very well be this is a brand new, never seen before type of attack, we see new attacks by the hundreds every week," said Colburn.
Since the malware wasn't found until Tuesday, it's unknown how big of a problem this might become.
"It's hard to guess, I would say to say as an added precaution to make sure all of our customers know about this so they can diligently watch their debit and credit card transactions," said Jozwiak.
The majority of stolen card numbers have been from Gold Canyon and Lake Havesu. Some are starting to pop up in Maricopa County as well.
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