The personal and financial information of approximately 110 million people, comprising 11 GB of data, was stolen in a successful compromise during the Christmas shopping season. The attackers persisted undetected for almost 2 weeks, and is attributed to a cyber criminal in the Ukraine. None of the anti-virus solutions on the market would haveor diddetect the malware, dubbed Trojan Trojan.POSRAM, a variant of BlackPOS. It’s possible that attackers abused a vulnerability in the web application to gain a point of presence and escalate privileges.”]
Source: https://securityintelligence.com/target-breach-protect-against-similar-attacks-retailers/