The use of another party’s computer to mine cryptocurrency without their consent.
Some cryptocurrencies are mineable, meaning that people can choose to expend their computational resources to secure the operation of the blockchain and earn newly created coins in exchange; the coins can later be traded on crypto exchanges for traditional currencies like USD. This requires the purchase, setup and maintenance of specialized equipment and significant expense of electrical power, all of which eat into the profit made from selling the mined coins.
Instead of participating in fair competition, an unscrupulous hacker may choose to mine cryptocurrency by hijacking the computational resources of other people, a practice known as cryptojacking.
Cryptojacking can be performed in multiple different ways, but there are two most popular ones. The first way is via a trojan — a malicious program that gets installed onto a computer without the owner’s knowledge or consent by, for example, clicking on an email link or attachment. The program then keeps running on the host computer, consuming its resources, while the profits go to the hacker.
Cryptojacking leads to increased consumption of its victims’ electrical power, slows down their computers and shortens the life of their equipment. If a user suspects that their computer might have been the target of a cryptojacking attack, they should look out for red flags: decreased performance and the overheating of their computer, which is usually coupled with more intense use of the cooling fan. Most modern antivirus software providers are acutely aware of the threat of cryptojacking, so they offer protection from it.