TJX, the owner of popular discount clothing chains like T.J. Maxx and Marshalls, has had their credit and debit card systems hacked. In an announcement, the company said the intrusion was discovered in mid-December 2006 and that it affects its T.J. Maxx, Marshalls, HomeGoods and A.J. Wright stores in the United States, Puerto Rico, Canada and the United Kingdom.

The company says an intruder gained access to credit card, debit and return item transactions for 2003 and mid-December 2006. In addition to credit card information, TJX believes the intruder also had access to driver’s license information. Some stores ask for identification and write down the customer’s driver’s license number on the top of checks.

The Department of Justice, Secret Service and the Royal Canadian Mounted Police are helping TJX in tracking down the hackers. TJX has also hired General Dynamics Corporation and IBM to help plug the security holes.

TJX has set up toll-free phone lines in the United States, Canada, the United Kingdom and Ireland to assist customers with any questions.