Target today claimed malware infected its cash registers, which allowed crooks to siphon off copies of 40 million credit and debit cards.
Chief executive Gregg Steinhafel said point-of-sale (POS) systems were compromised by a software nasty, which harvested sensitive banking information from customers' magstripes. The infiltration went undetected from late November through 15 December all over the US.
"There was malware installed on our POS registers, that much we have established," Steinhafel said in an interview with CNBC.
"This investigation is ongoing and it is going to take some time before we understand the extent of what has happened."
The company first gave notice of the breach late last year, warning customers who made purchases at Target between 28 November and 15 December that their cards were vulnerable to cloning.
As the investigations continued, the scale of the assault on Target grew. Encrypted banking card PINs were found to have been stolen as well, and a customer database holding names, addresses and phone numbers of 70 million customers was also ransacked.
The company has since vowed to cover any fraudulent charges connected to the breach, and foot the bill for credit-monitoring alerts and identity-theft protection for one full year for those affected by the scammers. While Target has yet to put a dollar amount on its costs, the company has already warned investors that the incident is likely to bring a hit to its bottom line.
Target may not be the only company to be infected by the breach. Luxury department store Neiman Marcus said that it had lost customer data as the result of a cyber-security breach on its systems over the holiday shopping season.
While no formal connection between the incidents has been announced, early reports suggest that the breaches carry evidence of being a coordinated operation. Researchers also have reason to believe that other retail chains were also targeted in the operation and that further disclosures are likely forthcoming in the next few days.
Should the suspicions of researchers be confirmed, the breach may well go down as the largest and costliest retail hack in history, topping even the 2007 breach of retail giant TJX's payment card systems. ®