One of the four individuals indicted for their part in a multimillion-dollar fraud scheme targeting more than 200 U.S. merchants has been sentenced to 21 months in federal prison, Bank Info Security reports.

The four Romanian men were said to have targeted the computer networks of these businesses over the course of two years, including national sandwich chain Subway, compromising an estimated 40 million debit and credit cards. The attacks occurred between 2008 and 2011.

According to federal authorities, the men remotely hacked into the POS systems to steal this private data, leading to what is believed to be millions of dollars in fraudulent purchases.

“Gartner analyst Avivah Litan, a fraud expert, says attacks against retailers’ networks or computer systems, which affects a database that has stored or temporary files containing sensitive information, continue to plague the industry,” the news source reports.

With instances of fraud on the rise worldwide, and the methods of hackers and cyber criminals constantly evolving and becoming more sophisticated, merchants must remain vigilant about their system defenses. Using credit card processing software that meets the latest in security standards and can work with any POS hardware or payment processing company is critical.

Not only does it provide companies with the best way to encrypt and protect customer data currently available, but it also offers versatility and the ability to switch hardware or processing vendors if security concerns prove too worrisome.

Furthermore, as new technologies and developments in this area come to market, a card processing software provider who also offers technical support without piling on additional fees is always a good thing to have.