Point-of-sale (POS) attacks remain a huge problem for companies. As noted by Threatpost, POS hacks have resulted in more than 20 million stolen bank cards as attackers shift from more traditional malware to undermining POS systems themselves.

According to Trend Micro, however, there’s a new brand of POS threats on the horizon: tag-team attacks that use a combination of multicomponent backdoors and multiple malware strains. Here’s the rundown.

POS Threats Mix It Up

It all starts with popular backdoor TinyLoader, which is often used to introduce secondary device infections. With a screen grabber and process enumerator, TinyLoader analyzes infected systems and determines if they’re eligible candidates for a secondary POS infection.

In November 2015, Trend Micro researchers found AbaddonPOS was the go-to payload linked to TinyLoader. But in January 2016, they noticed something strange: The backdoor was also fetching TinyPOS. Their conclusion? The two strains are somehow related.

Beyond intellectual curiosity, however, there’s a larger issue: adaptability. Until recently, companies compromised by TinyLoader could take steps to address Abaddon, but the introduction of this second strain gives POS threats the upper hand. Introduce a handful more and it becomes almost impossible to know what’s being delivered, when it attacks and how it will affect POS networks.

Eat the World

One candidate for a new threat team-up is the recently discovered Multigrain POS malware. According to SC Magazine, not only does it seek out systems running a particular POS process — making it a perfect fit with TinyLoader’s targeting process — but it also deletes itself if the process isn’t found.

More worrisome? Once Multigrain grabs payment card data, the malware strain transmits it to command-and-control servers using the Domain Name System (DNS) instead of HTTP or FTP. While companies have invested time and money in securing and monitoring HTTP and FTP channels, DNS is typically given free rein, making it an ideal avenue to both obfuscate and exfiltrate.

POS systems will always be high-priority targets for cybercriminals. Although the days of smash-and-grab POS malware have come and gone, criminals are now trying new tactics — such as tag-teaming malicious processes and using unexpected transfer routes to work around security defenses.

Bottom line? Tiny teams can mean big trouble for POS systems, especially those already infected by a known malware strain. There’s no safe spot and no movement method or process that won’t be corrupted by attackers when they see an opportunity. While not exactly heartwarming for security pros, the TinyLoader triumvirate serves as timely warning: POS threats are more popular than ever.