{"id":19676,"date":"2018-04-03T02:00:33","date_gmt":"2018-04-03T10:00:33","guid":{"rendered":"https:\/\/ahrefs.com\/blog\/?p=19676"},"modified":"2021-10-19T02:50:54","modified_gmt":"2021-10-19T07:50:54","slug":"cryptomining-study","status":"publish","type":"post","link":"https:\/\/ahrefs.com\/blog\/cryptomining-study\/","title":{"rendered":"How many websites are mining cryptocurrency? We analyzed 175M+ domains to find out."},"content":{"rendered":"
Did you know that some websites are using your<\/em> computer to mine cryptocurrency? We analyzed our entire index of 175M+ domains to find out exactly how many.<\/div>\n

I\u2019ll be honest, up until a few weeks ago, I didn\u2019t know there was such thing as a \u201ccrypto mining script\u201d that can be installed on your website.<\/p>\n

So let me briefly explain how crypto-mining scripts work. (I\u2019ll try to keep it simple.)<\/p>\n

For cryptocurrencies to function, complex computational calculations have to be continually carried out; this process is called mining<\/strong>. Mining is carried out by miners, who earn cryptocurrency by doing so.<\/p>\n

It takes a lot of computational power to mine cryptocurrency, which means a lot of energy.<\/p>\n

Because energy costs money, some websites install scripts that effectively utilise your computer\u2019s energy to mine cryptocurrency on their behalf. So, the longer you have their site opened in your browser, the more coins they earn using your computer\u2019s energy. (Clever, right?)<\/p>\n

Sidenote.<\/div> It\u2019s not always the website owners who install these scripts; many are simply hacked.<\/div>\n

Since cryptomining is such a hot trend right now, we thought it would be interesting to find out not only how many sites in the world have crypto-mining scripts installed, but also how many have enough traffic to make this a worthwhile endeavor.<\/p>\n

Let\u2019s get to the results!<\/p>\n

Our study<\/h2>\n

We crawled all 175,251,729<\/strong> websites in our database<\/a> to see how many were mining cryptocurrency.<\/p>\n

To clarify, this means that we crawled subdomains, too.<\/p>\n

To check for the presence of crypto-mining scripts, we used Wappalyzer<\/a>.<\/p>\n

For those unfamiliar with Wappalyzer, here\u2019s what it does:<\/p>\n

Wappalyzer is a cross-platform utility that uncovers the technologies used on websites. It detects content management systems, ecommerce platforms, web frameworks, server software, analytics tools and many more.<\/p><\/blockquote>\n

Wappalyzer can identify the presence of 14 common crypto-mining scripts.<\/p>\n

These scripts include Coinhive, Crypto-Loot, JSECoin, ProjectPoi, and many more<\/a>.<\/p>\n

Sidenote.<\/div> It\u2019s not important to understand how each of these scripts differ. They all mine cryptocurrency and work in roughly the same way.<\/div>\n

You can test Wappalyzer for yourself here<\/a>.<\/p>\n

Enter a domain and it tells you what technologies are being used on that website.<\/p>\n

\"wappalyzer

looks like there are no cryptocurrency mining scripts present on Ahrefs.com. (Phew!)<\/p><\/div>\n

But let\u2019s get to the results, shall we?<\/p>\n

Our results<\/h2>\n

We found 23,872<\/strong> unique domains running cryptocurrency mining scripts.<\/p>\n

As a percentage of the total 175M+ in Ahrefs\u2019 database<\/a>, that\u2019s 0.0136%<\/strong>. (Or 1 in 7,353 websites.)<\/p>\n

In terms of the actual crypto-mining script these sites are running, Coinhive<\/a> is the most popular option by far. It accounts for 93.82% of our results\u2014that\u2019s ~22,396 websites.<\/p>\n

<\/p>\n

(We\u2019ll talk more about Coinhive later in the article.)<\/em><\/p>\n

Let\u2019s take a deeper look at our data to glean some additional insights.<\/p>\n

1. How many monthly organic search visitors do these sites get?<\/h2>\n

Here\u2019s a breakdown of the monthly organic search traffic distribution for these sites (as estimated by Ahrefs):<\/p>\n

see the raw numbers for this graph here<\/a>.<\/p><\/div>\n

IMPORTANT!<\/strong> This IS NOT the total traffic; it\u2019s estimated monthly organic search traffic. This means estimated search traffic from Google alone.<\/p>\n

You can see that ~91% of websites that have crypto-miners installed are estimated to receive <50 visitors from Google each month\u2014not many at all!<\/p>\n

To summarise, most of the sites running crypto-scripts probably<\/em> receive very little traffic.<\/p>\n

We can only speculate as to why this is, but here are a few thoughts:<\/p>\n

    \n
  1. Abandoned websites may get hacked:<\/strong> I touched on this earlier. Basically, many people set up websites and then quickly lose interest. These websites are then abandoned and left to rot. Never do they have chance to attract a significant amount of traffic. Because they\u2019re left abandoned, it\u2019s likely that the CMS, theme, and plugin(s) won\u2019t receive any critical updates. This leads to security flaws which in turn, make it easier for hackers to gain access and install crypto-malware. So, while an individual website might only be getting a few dozen visitors per month, hackers may be able to mine a significant amount of cryptocurrency should they hack into, and install crypto-mining scripts on, thousands of websites. (But again, that is a pure speculation, as we didn\u2019t really dig into that.)<\/li>\n
  2. High-traffic have more to lose<\/strong>: Let\u2019s assume you have a website with a ton of monthly search traffic; wouldn\u2019t you avoid anything that may put your website at risk? Of course you would. There has even been rumours<\/a> in the past that Google might block websites with crypto-mining scripts in Chrome (a browser with ~58% market share<\/a>). Bottomline: installing crypto-mining scripts simply isn\u2019t worth the risk for high-profile websites.<\/li>\n<\/ol>\n

    2. How are these sites distributed across Domain Rating (DR), and how many of these sites are in top 100K by Ahrefs Rank?<\/h2>\n

    Let\u2019s first tackle Domain Rating (DR).<\/p>\n

    But what is DR?<\/p>\n

    Domain Rating (DR) is a proprietary Ahrefs\u2019 metric that shows the strength of a target website\u2019s total backlink profile (in terms of its size and quality). DR is measured on a logarithmic scale from 0 to 100, with the latter being the strongest.<\/p><\/blockquote>\n

    Basically, if site has high Domain Rating (DR), it means it has links from a ton of other sites. It\u2019s one way to measure the popularity of that website compared to other websites.<\/p>\n

    Further reading<\/div>
    \n