Like a crowbar, security software tools can be used for good and evil.
Bootleg versions of a powerful tool called "Card Recon" from Ground Labs, which searches for payment card data stored in the nooks and crannies of networks, have been appropriated by cybercriminals.
This month, the security companies Trend Micro and Arbor Networks published research into point-of-sale malware, which has been blamed for data breaches at retailers such as Target and Neiman Marcus, sparking concerns over the security of consumer data.
Both companies found that unauthorized copies of Card Recon had been incorporated into a malware program and a toolkit designed for finding and attacking POS terminals.
"Card Recon looks to be a useful tool when wielded by an auditor or security staff, but it is clearly dangerous in the wrong hands," Arbor Networks wrote in its report.
Card Recon is intended for organizations seeking to comply with the Payment Card Industry's Data Security Standard (PCI-DSS), a set of recommendations to safeguard payment card data.
The software tool scans all parts of a network to see where payment card data is stored. Often, companies find card details stashed in unlikely and unknown places. Card Recon compiles a thorough report, and companies can then move to secure the data.
The software requires license authorization before it will run, which prevents direct illegitimate use, said Stephen Cavey, Ground Labs' co-founder and director of corporate development, via email. But it's impossible to restrict access to Card Recon's software executable after a genuine customer has obtained it.
More than 300 security auditors worldwide and thousands of merchant companies use Card Recon, he said.
"This is the unfortunate reality for all software vendors: It is common for criminals to acquire a copy of commercial software via unauthorized means and then reverse engineer that software to circumvent the licensing mechanisms that are designed to prevent its unauthorized use," Cavey said.
Numaan Huq, a senior threat researcher for Trend Micro, wrote on Wednesday that a version of Card Recon dating from three years ago was being used to validate payment card details in a type of POS malware.
When Card Recon is scanning, it has to be able to separate 16-digit numbers and other random data it finds from valid 16-digit credit card numbers. Credit card numbers can be validated by using a checksum formula called the Luhn algorithm.
The malware Huq studied used Card Recon to validate and identify cards by brands such as Discover, Visa and MasterCard. Using Card Recon was faster than other validation methods, especially for large volumes of card data, he wrote.
Arbor Networks wrote in its report that the attack toolkit it observed contained two cracked copies of Card Recon. In that instance, it appears Card Recon was being used for its intended purpose -- to find card numbers -- but for cybercriminals.
If anything, the abuse of Card Recon strengthens a case for its legitimate use. Ground Labs' Cavey said the best defense is to remove sensitive data.
"They can't steal what is no longer there," he said.