A payment card industry security consortium warned retailers on Wednesday of the urgency to secure their systems against "Backoff," a malicious software program that steals card numbers.
Backoff "represents a very real threat to the security of cardholder data in all organizations," wrote the PCI Security Standards Council, an organization founded by MasterCard, Visa, American Express and other card companies.
The U.S. Secret Service and Department of Homeland Security warned last week that 1,000 U.S. businesses may be infected by Backoff, which wasn't detected by most antivirus security software until earlier this month.
The retail industry has been shaken by attackers who have successfully installed malware on point-of-sale devices that process card payments, including Target, Neiman Marcus, White Lodging, Michaels and UPS store.
Card breaches have been reported by Supervalu and P.F. Chang's China Bistro, while several other companies have ongoing investigations into suspected breaches.
Card companies require companies to be compliant with the extensive security requirements issued by PCI-DSS or face liability for fraudulent purchases. But despite passing PCI audits, many companies have been hacked nonetheless, with attackers still finding network weaknesses.
The PCI Council recommended that companies check with their antivirus vendor to make sure their product detects Backoff and run a scan immediately. The organization also advised to "review all system logs for any strange or unexplained activity, especially large data files being sent to unknown locations."
Retailers should also refresh their passwords and change default ones, a long recommended security practice but one which still catches companies off guard.
Other recommendations made by the PCI Council may not be so easy or cheap. It recommended that merchants use card processing devices that encrypt data immediately after it is captured.
Several types of malware found on point-of-sale devices are so-called memory "scrapers," which capture the card data while it is held unencrypted in memory. The weakness is prevalent in retail POS devices on networks that pass PCI-DSS audits.
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