You could be dealing with a crypto-miner that uses your video card’s processing power to, well, mine Bitcoins.

If you do not see any improvements after a reboot, then it’s the doings of malicious code. The system can get slow for no reason sometimes, and a restart usually fixes that. That’s especially true when pop-ups appear outside of the browser and take over the system. If you see ad pop-ups that you haven’t seen before, that’s probably the work of adware. It’s really easy to “figure out” this sign. And recently, they became a real problem for the fans of macOS as well. Adware attacks have always been a big headache for Windows users. And now that we know how malware usually infects the macOS, let’s talk about the most common signs in more detail: Or, maybe you’re dealing with pirated apps, and they are the root of the problem.

So, most likely, you’ve downloaded a file/program from a less-than-legit source. True, browser-specific exploits can be a threat, but if the OS is running the latest updates, you should be OK. The App Store is impenetrable, and the chances of being infected by an app that you downloaded from there are next to none. Is your system running slower than it should? Do you see suspicious pop-ups (with ads) all over the place? Chances are you’re dealing with Mac-exclusive malware that has planted itself deep into the OS. The virus installs itself, damages the software, and then continues to spread through the system. A virus is a stand-alone program that is installed against the will of a user on the device.

How to scan your mac for viruses