Retailers working to determine if a large cache of credit card information was offered for sale on an underground trading forum. Incidents involving Point of Sale malware have been on the rise, affecting many large organizations. Illicit markets exist for such information so that attackers are able to easily monetize stolen data. Maintaining externally facing systems to be fully patched, protected by a firewall, and conducting regular penetration tests to identify potential vulnerabilities helps to minimize the chances an attack will succeed. Security teams must remain vigilant for such activity, yet be able to distinguish false positive results from usual network traffic.”]
Source: https://blog.talosintelligence.com/2014/09/danger-at-retail-point-of-sale.html