Most everyone remembers those old Mac vs. PC commercials where a smooth-talking Justin Long belittled the dowdy John Hodgman, most often about susceptibility to viruses. Apple has long touted a near invulnerability to attack, telling users that they are much, much safer using Mac products than relying on anything that could be called a PC.

That is simply no longer the case. Not only are instances of Mac malware increasing rapidly, but hackers are finding ways to develop malware that covers both bases. Just this past week, researchers from Trend Micro identified an active Mac malware that easily slides past Mac’s built-in security thanks to its history attacking Windows. Here’s what that means for Mac and PC users who want to stay safe.

How the Malware Works

In the past, there was Mac malware, and there was Windows malware. PCs and Macs had vastly different operating systems that required different programming for malware – specifically, EXE file formats can only run on Windows – meaning if hackers wanted to attack both PCs and Macs, they would need to write and deploy two programs. The reason Apple got away with calling PCs virus-riddled for so long is that Windows was an easier and more lucrative target for cybercriminals; the sheer volume of PC users made it more likely that a piece of Windows malware would find success. Macs have long been carriers for Windows viruses, but because of their unique OS, they didn’t suffer any of the irksome symptoms endured by PC users.

Until now. What Trend Micro discovered in early February was wild EXE files delivering payloads on macOS machines. The greatest concentration of infections are occurring in the U.K., Australia, South Africa, the U.S., Armenia and Luxembourg. The malware seems to lack a specific attack pattern, but when the program is installed, it collects system information such as model name, processor speed, memory and serial numbers as well as information stored in various apps, like Photos, Notes, iTunes, Messages and even Calculator.

Trend Micro believes that the malware was launched as an experiment by malware developers, who hope to improve on the code for multi-platform attacks in the future. Currently, the malware doesn’t work on Windows; despite its EXE files, the malware only displays an error notification when installed and executed on a PC. Still, now that cybercriminals have cracked EXE files on macOS, it is ever more likely that malware for both Macs and PCs will soon emerge.

What It Means for Mac Users

In truth, it should hardly be surprising to any Mac user that another Mac malware has been uncovered. Malware for Apple products have been increasingly rapidly since the mid-‘00s, when popularity of the platform increased. Unfortunately, at that time, the propaganda from Apple regarding the inherent security of their devices lulled Apple users, meaning most have failed to develop the security savvy they need to survive in a malware-filled world.

Though the amount of malware designed for Macs remains negligible when compared to the hordes of malware targeting PCs, Mac malware tends to be more successful than PC malware because Mac users lack both the proper antivirus software and the cyber hygiene to stay safe. This new threat could mean that Mac malware will increase to rates akin to those currently plaguing PC users, which means the sooner Mac users equip themselves with security knowledge and tools, the better.

What It Means for PC Users

For PC users, the news that Windows files are being used for Mac malware shouldn’t mean much. Already, PCs are hackers’ main targets, and PC users are accustomed to fending off malware from every which way. Though the opportunity for cybercriminals to develop multi-platform malware is frightening, it shouldn’t much change how PC users approach security; the same antivirus software and safe browsing habits will continue to serve them well.

However, for both Mac and PC users, this development should stand as evidence that malware creators are getting smarter and learning new tricks for overcoming established security. That means it is more important than ever to pay attention to basic security rules, like updating software, avoiding suspicious links and downloads, making long, unguessable passwords and choosing to connect only to private, secured networks. Even if the programs become more powerful, these tricks are likely to keep most device users totally safe.