Breach at Neiman Marcus Went Undetected From July to December

The computer network at Neiman Marcus was penetrated by hackers as far back as July, and the breach wasn't fully contained until Sunday, according to people briefed on the investigation. The company disclosed the data theft late last week, saying it first learned in mid-December of suspicious activity that involved credit cards used at its stores. It issued another notice on Thursday, elaborating slightly. The latest notice said that "some of our customers’ payment cards were used fraudulently after making purchases at our stores. We've taken steps to notify those affected customers for whom we have contact information."