With the largely profitable possibilities, miner viruses are seen more often in the pirating sites. Imagine the profit that you can make off having your miner spread to let's say 10k people around the world? LARGE amount! Now comes the question, why are the pirates the most targeted ones? Well, who else has high-end GPU's and CPU's? I mean, they are the perfect target for making high profits!
Now, how to detect the miners? If you are lucky and the virus is older, then probably your antivirus will detect it. But what to do if it's not detected and you are experiencing symptoms like unexpected fan activity, mostly happening when there's no activity and mouse movement?
If the miner has DDOS function integrated, another symptom could be high ping without any reason (of course, check whether your brother downloads torrents first).
HOW TO IDENTIFY MINERS?
Now that your antivirus failed to detect a miner you should do it manually.
You can try identifying miners by using the task manager (you can start it by right clicking on the taskbar and selecting 'Start Task Manager').
Now after starting the task manager what you want to look for is the CPU % usage while there are not high consuming programs loaded, preferably none. In the picture above, the levels are normal for me, as they are always that low when I am not loading high consuming programs. Now if your CPU usage is high you should examine the running processes and look for an unfamiliar process. I mostly look for their name AND file location.
Now, if you find something then you can try different methods of deleting it but I am not going to discuss that here since this guide is for just identifying miners.
SAFETY TIPS
The best thing you can do to protect yourself from this viruses is to be more aware and avoid downloading pirated content, mostly pirated games. Although people will tell you the cracks are intended to be detected as viruses so you should add them to the exceptions list in your antivirus, they may ACTUALLY have a real virus injected into them.
Mostly cracks will be detected with different names than their actual virus names due to the usage of crypters which are used to avoid detection (or decrease the rate). And last but not least, update your antivirus definitions to the latest so you won't have to face new viruses!