Malwarebytes is a company that we know for developing software that helps improve user safety. In full Bitcoin fever , they have shown a systemthat allows you to mine cryptocurrencies even if you have closed the browser.
The browser is the epicenter of the computer for many users, since most of its activity is focused on this tool. They say that ‘money does not grow from trees’ , but currently it does in a tab of our browser.
In recent months we have seen some websites, taking advantage of Coinhive (a program based on Javascript and specific for Monero), were engaged in mining cryptocurrencies without notifying us. Malwarebytes wanted to warn that they have found a way to continue doing it even if we have closed the browser.
They have tested this technique in Windows and with Google Chrome, and say that the results may vary in other browsers. The operation is as follows:
- We entered a web that, without notifying us, mine cryptocurrencies.
- CPU activity goes off
- We left the web and closed the Chrome window
- Activity the CPU is still above normal, as they continue to undermine cryptocurrencies
A simple and effective trick
To achieve this, they have created a pop-under that hides under the clock in the taskbar . The coordinates of this small window will vary according to the resolution of each user.
If your Windows theme allows the taskbar to have transparency you will see this window so furtive. Otherwise, there is another way to expose it. You will simply have to change the size of the taskbar so that it appears (both in Windows 7 and in Windows 10).
Obviously, the pages that mine cryptocurrencies have a big problem: they can not continue doing it when you have closed the browser. With this type of techniques they are trying to overcome this obstacle, although there is a simple way to avoid it.
If we have closed the browser and see that the CPU is still above normal, we simply have to go to the task manager and kill those processes that are causing it. It will also depend a lot on the type of pages we visit, although surely this type of practice is more and more common.
What is clear to us is that the creators of malware are still looking for ingenious and sophisticated ways to take advantage of our computers. The eternal game of cat and mouse.
