AutoNation recently began notifying an undisclosed number of customers that their personal information may have been accessed when a third-party vendor's system was hacked.

Visitors to three sites hosted and operated by e-commerce and data services provider TradeMotion -- AutoNation Ford White Bear Lake Parts, AutoNation Toyota South Austin Parts, and Discount Toyota Parts -- were affected when hackers accessed credit card information as it was entered into TradeMotion's system between March 5, 2014 and May 2, 2014.

The information potentially accessed includes customers' names, addresses, e-mail addresses and credit card numbers.

"We understand from TradeMotion that it has removed the software used by the hackers to access this information and is monitoring its systems for any ongoing activity," AutoNation chief operations counsel Guillermo Pernas wrote in the notification letter [PDF]. "It is also conducting penetration testing and is monitoring its systems for any additional unauthorized activity."

All those affected are being offered one free year of identity theft protection through Experian's ProtectMyID.

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