Sunday (Dec. 15) was really day one. That was the day we confirmed we had an issue and so our number one priority was ... making our environment safe and secure. By six o'clock at night, our environment was safe and secure. We eliminated the malware in the access point, we were very confident that coming into Monday guests could come to Target and shop with confidence and no risk.While it was confirmed that malware attacking Target's POS registers was at fault, it
Day two was really about initiating the investigation work and the forensic work ... that has been ongoing. Day three was about preparation. We wanted to make sure our stores and our call centers could be as prepared as possible, and day four was about notification.
did not disclose the actual methodology behind the hack.
However, sources speaking to Reuters said the hackers attackers used similar techniques in all the attacks. One of the tools was what is known as a RAM scraper, or memory-parsing software, which grabs data from live RAM where it is transmitted "in the clear" (unencrypted).
Interestingly, Visa issued two alerts about these types of attacks last year, in April 2013 (.PDF) and again in August 2013 (.PDF).
Although Target said on Friday that since the data breach was announced, the company had seen "meaningfully weaker-than-expected sales," Steinhafel said that, as that day, Target's "shopping trends" were nearly back to normal.