I'll let it go because I personally distrust all of this, crypto-currency and even blockchain, because blockchain is a public ledger and I prefer to keep my books private (it's not a privacy solution, as the authorities have proven many times) Easy enough to dox.
https://www.wpsdlocal6.com/news/hackers-mining-for-bitcoin-using-other-peoples-computers/article_69870eca-3f2e-11ea-9a8f-97f9c90dc773.html
Bitcoins are "mined" using super-computers that work to solve nearly impossible math equations. This takes an enormous amount of processing power. Computers built to mine cryptocurrency cost in excess of $5,000. Rather than buying those computers cyber-criminals are hijacking the computers of random people to do the work for them.
Malware is put on a computer by tricking the user into clicking a link in an email or on a website. The malware allows the hacker to begin using any processing power the computer user isn't using at that moment. If they leave their computer on when they go to bed at night for example, the computer can work through the night using all of its processing power to help the hacker mine for bitcoin. The malware code is available on the Dark Web for $20-$30 and it's easy for a hacker to run a program that installs it on a remote computer. It can even be installed on a computer sharing the same public wifi network.
Many websites have crypto-mining software on them that will use the extra resources of the computer that's connecting to the site. One recent study showed 1 out of 50 websites contain crypto-mining code, and it's also been discovered in ads on YouTube videos.
It will likely go unnoticed but most of the time an infected computer will begin to run much slower. It may also run hot which will be noticeable due to the fans running longer or louder than normal. You would also likely see an increase in your electric bill since the computer will be working harder and running constantly.
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