Cryptocurrency mining (cryptomining) is legitimate and is a critical part of how cryptocurrencies work.

Cryptomining uses the processing power of computers to solve complex mathematical problems, and verify cybercurrency transactions. The miners—­­­­who are like auditors—are then rewarded with a small amount of cybercurrency.

This step ensures the validity of the currency, with no one able to use the same money twice. The miners keep cryptocurrency users honest!

The method to verify these transactions takes a lot of processing power and even when cryptominers use dedicated computers, they don't usually earn very much.

Cryptomining malware

To earn more, dodgy cryptominers use cryptomining malware to try and hack into people's computers and use their computer's processing power, often without them knowing. This is when cryptomining becomes illegal.

The malware can slow computers down dramatically and stop them working normally.

Does my computer have cryptomining malware?

The recent surge in cryptocurrency prices means cybercriminals are increasingly targeting different platforms—Android, smart devices and Windows—in an effort to earn more.

If your device is infected, it will be slower and struggle to perform some normal tasks, as the malware is using its processing power.

How could my computer become infected?

Cryptomining malware infects computers and networks in the same ways as other types of malware:

  • attached to an email
  • hide on genuine or fake websites
  • pretend to be an application on a peer-to-peer network.

In early 2018, cryptocurrency miners infected Google's ad network with malware to tap into the processing power of those who looked at ads on YouTube. 

Protect yourself from cryptomining malware

Follow these steps to reduce your risk of being affected by cryptomining and other malware:

  • Use anti-virus software and automatically download updates. 
  • Use to block malicious activity. (Browser add-ons allow your browser to do more things.)
  • Keep software such as your operating system and applications up-to-date. 
  • Use strong passwords.
  • Never click on links in emails or messages you aren't expecting, even if it looks like it comes from a government agency, well-known organisation, or even a friend.
  • Disable Microsoft Office macros. (Macros are small programs used to automate simple tasks in Microsoft Office documents but can be used maliciously. Visit the Microsoft website for information on disabling macros in your version of Office).
  • Browse the web safely.

More information

Sign up to Stay Smart Online's Alert Service to get information on the latest threats, and how to protect yourself.