3 U.S. retailer was vague in providing details about what it knew and when. The company has so far disclosed that the breach started in late November and lasted 19 days over the peak holiday shopping season, resulting in the theft of about 40 million credit card records and 70 million other records containing customer data. Target was not the only US retailer to suffer a security breach during the holiday shopping season. The security breach, which yielded the personal information of as many as 110 million customers, was first identified on December 15, four days before the breach was publicly revealed, CEO Gregg Steinhafel told CNBC during an interview. That was the day we confirmed we had an issue and so our number one priority was ... making our environment safe and secure," Steinhafel said in the interview. Another retailer, Neiman Marcus, disclosed on Friday that it was warned about a possible breach in mid-December and that an outside forensics firm confirmed a breach on January 1, saying it found evidence that some payment card data may have been compromised. Smaller breaches at least three other well-known U.S. retailers took place over the holiday season and were conducted using similar techniques as the one on Target, according to the people familiar with the attacks. Hackers infected Target's point-of-sale terminals with malware to steal the payment card information from millions of customers, the retailer's chief executive has confirmed.
– Victims of the Target hack were hit as they slid their payment cards through point-of-sale terminals, says the company's CEO: That's where hackers placed their malware, Gregg Steinhafel tells CNBC. On Sunday, Dec. 15, the company recognized "we had an issue," and "by six o'clock at night, our environment was safe and secure. We eliminated the malware in the access point." Steinhafel explained why it still took a few days to alert customers, CNET reports: "Day two was really about initiating the investigation work and the forensic work," while "day three was about preparation" of stores and call centers. After Neiman Marcus revealed that it, too, was hit with a data breach, Reuters reports that three other top US retailers were also victimized, though on a smaller scale. Insiders say the people behind the scam may have been the same ones who hit Target. Details remain hazy, but Reuters' sources say the other retailers had mall outlets. Earlier attacks may have worked as trials ahead of the Target hack, notes a security expert. One technique hackers may have used is called RAM scraping, during which hackers collect encrypted data when it's in plain-text form in a computer's memory.