In-Browser Mining: Creating crypto with your browser

In-Browser Mining: Creating crypto with your browser

There seems to be a new (malicious) trend for mining different cryptocurrencies. It is commonly called “In-Browser Mining” and works pretty easy using Javascript libraries like e.g. coinhive.com (website doesn’t run in-browser mining directly!) does. Coinhive is mining a cryptocurrency called Monero. But this is by far the most good-natured example because the site asks you how you want to mine. Normally, this doesn’t apply at all to the other sites which use you as a tool for their business.

Abusing your precious CPU

I personally experienced this when I stumbled upon some sites and realized that my fan turned on. It took me quite a while to figure out what the problem was. I saw that one site opened in the background in a new window and caused high CPU usage on my machine. These pages are often called In-Browser Mining websites which solve blockchain hashes using your CPU. This is absolutely annoying since you waste your computing power to mine coins for somebody else. To find out if you are really mining with your browser, you can try to inspect the source code of the site. If the site loads suspicious Javascript libraries or includes an useless iframe, these could be hints for In-Browser Mining. For the coinhive.com site it was very obvious as you can see in the figure below.

Hints for mining websites
Hints for mining websites

Quick Solution

If you ever experience this, I recommend using the browser task manager (Chrome: shift + escape) and looking for the tabs with high CPU utilization. You can close that website from the task manager.

mining in browser
In-Browser Mining with your CPU on coinhive.com