With the dawn of cryptocurrency, a new form of hijacking has emerged. A way to steal power and resources from a computer to be used for bitcoin mining. Cryptojacking, can be done on any device that is able to browse the internet. It, however, leaves no traces of it happening that the victim will be aware of other than lowered performance. It simply harnesses the victims' machine to "mine" cryptocurrencies' blockchains, that create tokens and generate fees for the attacker, while the costs of electricity and wear and tear to the device are absorbed by the victim.
In order to fall victim to cryptojacking, it used to mean unknowingly installing a program that would work secretly in the background to mine cryptocurrency. But in recent times that may have changed.
As of now, there is no way to actually monitor if a computer is being hijacked. So the best option to avoid it is to install a cryptojacking blocker. A cryptojacking blocker adds a browser extension that blocks the most common domains that have cryptojacking code.
NoCoin is currently the most widely used extension created by Rafael Keramidas. It has extensions for both Chrome and Firefox and can be considered the most comprehensive with at least five contributors updating the list.