Cybercriminals are targeting employees who browse the Web or check their email from point-of-sale (PoS) computers, a risky but unfortunately common practice.Researchers from security firm FireEye recently came across a spam campaign that used rogue email messages masquerading as job inquiries.The emails had fake resumes attached that were actually Word documents with an embedded malicious macro. If allowed to run, the macro installed a program that downloaded additional malware from a remote server.Among those additional programs, the FireEye researchers identified a new memory-scraping malware threat that steals payment card data from PoS terminals. They've dubbed the new threat NitlovePOS.PoS malware has become commonplace over the past few years and has led to some of the largest credit card breaches to date. This kind of malicious program was used to steal 56 million payment card records from Home Depot last year and 40 million from Target in late 2013.Once they are installed on PoS terminals, these programs scan the system's memory for card data while it's being passed from the card reader to the specialized merchant application -- hence the term "memory-scraping." Criminals can use the stolen data to create fraudulent copies of the compromised cards.Attackers typically infect PoS systems with malware by using stolen or easy-to-guess remote access credentials. Another method is to first compromise other computers on the same network as the terminals and then to attack them.However, it's unusual to see PoS malware distributed through spam, like in the case of NitlovePOS, especially as part of a larger, indiscriminate campaign. This suggests that cybercriminals seek to exploit cases where employees use Windows-based PoS terminals to check their email or perform other risky activities."Organizations should educate their employees to follow best security practices, such as only using POS systems for what they are intended for and not to browse the web, check email, play video games, etc.," researchers from security firm Trustwave wrote last month in a blog post that advised organizations on how to protect their systems against a memory-scraping memory program called Punkey.