Cryptomining malware, also called cryptocurrency mining malware or simply cryptojacking, is a relatively new term that refers to software programs and malware components developed to take over a computer's resources and use them for cryptocurrency mining without a user's explicit permission. Unauthorized cryptomining is seeing exponential growth, since it actually doesn’t require significant technical skills and cyber criminals have increasingly turned to cryptomining malware as a way to harness the processing power of large numbers of computers, smartphones and other electronic devices to help them generate revenue from cryptocurrency mining. Ad blocking firm AdGuard, for instance, estimates that more than 500 million users are mining cryptocurrencies on their devices without realizing it. These users either get infected by a cryptomining malware program or visit websites that stealthily run cryptomining software in the background without the user's consent.

While many cryptomining malware and cryptojacking programs target desktops and laptops to mine cryptocurrency, others target smartphones and tablets. One of the more powerful cryptomining malware programs, dubbed Loapi by Kaspersky Labs, is designed to hijack an Android smartphone’s processor and is so intensely invasive that it can overheat the phone’s battery and physically damage the device.

In addition, cyber criminals have turned to browser-based cryptocurrency mining as well to help them generate revenue from cryptomining. Although it is known to be in use since 2011, it has only recently become a widespread issue, due to its explosive growth as well as the launch of new browser-based cryptocurrency mining services in 2017, like e.g. Coinhive, which could be considered just another form of cryptocurrency mining malware.

Either criminals trick victims into loading cryptomining code onto their computers and then the script runs in the background, or the script gets injected on a website or an ad that is delivered to multiple websites. But unlike typical malware, cryptojacking scripts do no damage to computers or the victims’ data, instead stealing CPU processing resources.

Source: Webopedia