The inadvertent use, and therefore, not consented by the user, of the calculation power of a device to mine cryptocurrencies is what is known as cryptojacking, and extends as the fever for electronic coins continues to rise. 

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[Source](https://i1.wp.com/criptotendencia.com/wp-content/uploads/2018/03/cryptojacking-como-prevenirlo.jpg?w=696&ssl=1)

In October 2017, Malwarebytes reported 8 million daily malware blocks, each detected as possible cryptojacking.

According to the software company, the United States tops the list with 32 percent of all attempted cryptojacking traffic, followed by Spain, France, Italy and Canada.

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[Source](https://i0.wp.com/criptotendencia.com/wp-content/uploads/2018/03/cryptojacking-TOP-10.gif?resize=657%2C365&ssl=1)

How does cryptojacking happen?
Cryptojacking, also known as cryptocurrency secret mining, works in the following way: by visiting some websites that run mining scripts present in your code these are loaded into your browser, without warning. By running in this way they mine cryptocurrencies using their computer's CPU, earning money themselves or for someone else.

Detecting hidden mining

A classic symptom of cryptojacking, especially in smartphones and tablets, is the overheating of the device. The other is the rapid decrease in battery charge.

It should be clear that, in general, we are exposed to cryptojacking when we open a tab of our preferred browser and visit a website possibly hosting mining scripts, and not so much when downloading or installing software, although this variant should never be discarded. .

By not compromising the data contained in the device most of the antivirus have treated these scripts as "potentially unwanted programs", granting them a low level of danger.

What we can do

Being considered the cryptojacking as malware we can perfectly follow the general recommendations used to prevent infections of computer viruses or hacking on their devices:

Install an antivirus on your devices and run regular checks.
Keep the operating system of the device updated.
Pornography sites, torrent downloads, videos and online games are preferred by cryptojackers to host their scripts. Be alert
If you suspect that a website is undermining your visitors you can check it out in WhoIsMining .
Do not install programs from unknown or suspicious sources.
Make a backup of your data.
Do not use a program or app? Dismantle it. This minimizes the attack surface of viruses and other malware.
Public WiFi hotspots are risky. Be careful when using them.
Stay alert to alarm signals from your devices; if it consumes a lot of battery, or if the temperature rises well above the usual there may be a risk of cryptojacking.
In addition, we can help our browsers to avoid opening certain sites on the Internet, through local configurations. Let's see.

Stop the cryptojacking in all browsers

If you are using multiple browsers and you know the website that is using your system resource to extract the digital currency, you can block that website permanently from your PC. For Windows users, edit the hosts file to completely block those domains. For Windows users, go to C: \ Windows \ System32 \ drivers \ etc

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[Source](https://i2.wp.com/criptotendencia.com/wp-content/uploads/2018/03/cryptojacking-DOS.jpg?w=574&ssl=1)

Now edit the hosts file by right-clicking on it, and opening it with Notepad (you may need administrator access to edit this file). All you have to do is add the lines 0.0.0.0 coin-hive.com at the end as shown in the image. Write a similar entry for each site you want to block.

For Linux users, open the terminal and enter the sudo nano / etc / hosts command to edit the hosts file.

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[Source](https://i1.wp.com/criptotendencia.com/wp-content/uploads/2018/03/cryptojacking-Linux.gif?resize=590%2C348&ssl=1)

Add the lines add 0.0.0.0 coin-hive.com as the last line.

Finally, we can harden our system against secret mining, using applications and add-ons from browsers.

Programs and extensions that protect
Among the programs and browser extensions that help us create a defensive barrier against cryptojacking, and whose use is recommended, we find:

Malwarebytes

Malwarebytes is a powerful anti-malware software that keeps your computer safe no matter how dangerous the threats are. This security solution also blocks CoinHive, one of the most widespread cryptocurrency miners so far.

NoCoin

NoCoin is a very useful browser extension available for Chrome , Firefox and Opera, which prevents miners from using the processing power of their computer. The tool can block a wide variety of cryptojacking software, including CoinHive.

MinerBlock

MinerBlock is another extension that you can use to protect your computer's resources. This tool can block all cryptocurrency miners based on the web, regardless of their origin.

It is available for Chrome , Firefox , Opera, Safari and Android.

CryptoPrevent

CryptoPrevent is a small tool that you can use together with your main antivirus or antimalware solution. The program is compatible with Windows XP, Vista, 7, 8, 8.1, and Windows 10.

To complete this arsenal, we can also use tools that block Javascript extensions, such as ScriptSafe (Chrome), or NoScript (Firefox).

Mining executed for long periods of time can affect computers and mobile devices, especially those that are not adequately ventilated, and in this case a case of irresponsible use of software against the programmers of these scripts could be established, as it is damaged a device affected by cryptojacking.

The other point is the ignorance of the user, which violates any ethical practice.CoinHive has become aware of the situation and has modified the mining script, which now requests the authorization of the visitor, converting what was previously forced and hidden, in one option:

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<center>[Source](https://i0.wp.com/criptotendencia.com/wp-content/uploads/2018/03/cryptojacking-MIneria-Oculta.gif?resize=322%2C329&ssl=1)</center>

Even so, many security companies and several ad blockers have begun to block Coinhive and other cryptoming domains. Browser manufacturers have listened to user complaints about the intensive use of their CPUs, and are also adapting their products to offer better protection to invisible miners.