Claimed Home Depot credit card hack could be biggest retail breach yet

One of the US's largest home improvement chains is investigating whether its systems have been cracked by hackers, as one security researcher has claimed.

"I can confirm that we’re looking into some unusual activity and we are working with our banking partners and law enforcement to investigate," the company told El Reg in a statement.

"Protecting our customers' information is something we take extremely seriously, and we are aggressively gathering facts at this point while working to protect customers. If we confirm that a breach has occurred, we will make sure customers are notified immediately. Right now, for security reasons, it would be inappropriate for us to speculate further. We will provide further information as soon as possible."

According to security blogger Brian Krebs, multiple banks have reported that a large number of stolen credit and debit cards have appeared for sale online that appear to have come from Home Depot. The card numbers, on sale in the murky rescator.cc site, appeared in two large batches on Tuesday morning.

The purloined cards were on sale labeled "American Sanctions," presumably as a reference to the increased sanctions threatened by the West in response to Russia's involvement in the Ukrainian civil war. A similar batch of cards from EU banks was labeled "European Sanctions."

Banking contacts told Krebs that the financial data appeared to have been stolen between late April and early May 2014. If so, given Home Depot's huge network of stores, then this could be one of the biggest retail hacks in history.

Retailers are currently the flavor of the month with the criminal hacking community, with infected point-of-sale terminals the preferred method of harvesting. Last month, US CERT warned that this vector was being actively targeted and that both supermarket chain Supervalu and delivery firm UPS have reported being hit.

Point-of-sale malware is possible because the software such terminals use is usually poorly protected and they run old or outdated operating systems. Once installed, such malware can be difficult to detect and highly efficient at capturing data.

It might be hoped that the move towards a chip and pin regime in the US could blunt the effectiveness of point-of-sale attacks. But as Professor Ross Anderson told the Black Hat hacking conference this year, such systems are easy to fool and manufacturers show little interest in tightening their security. ®