If you complained to someone about your computer or a certain website being extremely slow, they might’ve told you that you that you should watch out for cryptomining attacks. But what does that mean? And what can you do about it?

If you missed it, please refer to our previous article, Cryptomining Myths And Facts. There we explained a few concepts, discussed myths and facts, and most importantly, mentioned our disclaimer. But just in case you’re too lazy to head back, here it is again:

Disclaimer: If you’re a professional person reading this, please don’t judge the way we explain things – we’re trying to explain it to the people who have no computer knowledge whatsoever. Like our moms. (Sorry, mom). Also, “miner” refers to the programmer that injects the mining software into websites.


Should I be afraid of cryptomining?

Certain websites have opted for cryptomining to earn extra revenue instead of bombarding you with annoying ads. If it’s a website you want to support, you enjoy not having ads popping up all over the place, and they notified you that they will be using a percentage of your computer’s processing power while you are on their website, there isn’t really any harm. It’s when they do this without your consent that it gets unethical and you are completely entitled to block them from using your computer to their benefit.


What can I do if I suspect cryptomining?

Although it is possible to infect a computer with mining malware, cryptominers would most likely just use your computer’s processing power through websites, not by infecting your computer. However, your computer might be infected with mining malware when you downloaded an infected file. It’s always a good idea just to run a security check with your anti-virus or anti-malware if you notice your computer is slow, just to be safe.


How to check for cryptomining

If you want to check for mining software yourself, here’s how you can do that:


Close your browser

The easiest way to determine if a website is using your computer to mine, is just to close your internet browser and check if your computer speeds up. If it does, one of the websites you were visiting might be infected with mining software. But closing your browser might not always work, as this article points out.


Check your CPU usage

Depending on the operating system you use, you can either search for Task Manager on Windows, or Activity Monitor on a Mac OS X, and observe how the CPU’s graph looks. If you see something like this, your CPU usage is at around 100% and you can be fairly certain your computer is being used for mining – especially if you have very little programs open:


Coin mining blockers

There are a few browser extensions you can install to block cryptomining:

  • No Coin (Chrome, Firefox, Opera)
  • minerBlock (Chrome, Firefox, Opera)
  • Anti Miner (Chrome)
  • Coin-Hive Blocker (Chrome)


These extensions blacklist known domains and mining scripts. They also have the option to whitelist the websites you don’t mind mining.



You can also install extensions that block advertisements to block mining scripts:

  • Adblocker (Chrome)
  • Adguard (FireFox)


Disable JavaScript

Because miners use JavaScript code to mine, you can avoid them by simply disabling JavaScript on your browser. However, this isn’t a very good idea because the vast majority of websites need JavaScript to run – even Facebook won’t work without Javascript.