Are Websites Using Your CPU for Cryptocurrency Mining?
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The rise and fall of cryptocurrency prices around the world catch the interest of almost everybody. That interest isn’t limited to just the technology world, either. Bitcoin (and other cryptocurrencies) are under constant scrutiny by the global financial industry.

And some people aren’t content with using their own resources to pay for or mine cryptocurrency — so they’re going to use yours instead. I’m not talking about a cloud mining scheme.

I’m talking about a world renowned piracy website co-opting your CPU power to mine Bitcoin for themselves. While not strictly necessary, you may want to learn about what CPUs are and how they work What Is A CPU and What Does It Do? What Is A CPU and What Does It Do? Computing acronyms are confusing. What is a CPU anyway? And do I need a quad or dual-core processor? How about AMD, or Intel? We're here to help explain the difference! Read More  before continuing with this article.

The Pirate Mining Bay

World renown piracy site The Pirate Bay was recently caught using a JavaScript-based cryptocurrency miner on some of its pages. The premise is simple: you log on to their site to find a file (legal or not, no differentiation is made between users). In the background, a code provided by Coin-Hive runs, converting your CPU power into Monero (a type of cryptocurrency) coins for the site administrators.

Numerous reports of sudden CPU spikes began rolling. The Pirate Bay administrators confirmed that they had trialed a Monero JavaScript miner because they “really want to get rid of all the ads,” adding that “we also need enough money to keep the site running.”

They mine Monero because it is impossible to mine Bitcoin with a CPU.

A Controversial Move

Of course, forcing your users to use their CPU power to mine cryptocurrency for you is absolutely going to divide opinion. Let’s briefly examine the opposing opinions.


There are a surprisingly large number of users encouraging and supporting The Pirate Bay.

the pirate bay double positive comment

This is for a few reasons, one of which is important: revenue. Given the content of The Pirate Bay, and the strict advertising rules laid out by Google (and other advertisers), attracting decent and wholesome advertising to TPB is difficult. There are more than a few comments suggesting this source of income would be worth opting in to and sharing CPU resources — if it meant a reduction (or the removal) of any adult content advertisements.

the pirate bay mining positive comment

Others suggest that regardless of advertising, many users can actually spare some power due to the general trend for increasing CPU power.


With the positive, there is a healthy chunk of negative.

the pirate bay mining negative comment

One of the main concerns is the underhanded nature with which TPB has approached this. While some users claim TPB long before informed users that the trial would be taking place, the vast majority see this as a sneaky cryptocoin grab at the expense of the users.

Per the comment above, some users would have been happy with the transition from adverts to CPU-powered crypto-mining, but are unhappy they weren’t warned it would happen.

CPU Mining or Adverts?

I’d like to say the question is as simple as looking at adverts or not… but it isn’t.

The adverts are fueling a pirate file sharing service. And whatever your beliefs, the vast majority of content shared on TPB is illegal. The administrators of TPB keep the site going through the multitudes of law enforcement and government scrutiny.

Adverts pay to keep the site alive. That said, they’re not the most unobtrusive adverts. Some of them are less than tasteful, to say the least — but bills are bills, and someone has to keep the lights on.

The flipside is sharing some of your CPU power with the website so they can mine Monero coins. While less visually intrusive (you can keep your retinas intact), is it appropriate to use the CPU power of every visitor to the site?

Therein lies another problem: consent. A regular site that serves malicious ads containing a JavaScript miner would be rightly derided. But because TPB serves up illegal content to millions of people (The Pirate Bay usually ranks in the top 100 sites in the world), users are happy to keep the site alive. Mining schemes might well be an excellent answer to TPBs revenue stream issues. But any distributed mining scheme has to be opt-in.

And while TPBs administrators confirmed there was “a small typo” in the code meaning that all unused CPU power was acquired for mining, even the corrected “20-30 percent” use rate could still cripple some machines. Let alone the additional wear and tear on your CPU, and the electricity to boot.

Don’t Wait for the Opt-Out

The Pirate Bay contend that the mining script was only a trial. However, there was no mention of an opt-out. Though, to be fair to TPB, there is chance to introduce one later down the line if they proceed. Regardless, you don’t have to wait for the opt-out. The JavaScript miner can be blocked Control Your Web Content: Essential Extensions to Block Tracking and Scripts Control Your Web Content: Essential Extensions to Block Tracking and Scripts The truth is, there is always someone or something monitoring your Internet activity and content. Ultimately, the less information we let these groups have the safer we'll be. Read More from running at all.

There are a few ways you can do this:

  1. Block or disable JavaScript in your browser settings. For instance, Chrome users can head to Settings > Content > JavaScript, and toggle Allowed. Alternatively, add The Pirate Bay to your block list.
  2. Use a script-blocking addon such as NoScript (Firefox) or ScriptBlock (Chrome).
  3. Specifically block the miner URL using an ad-blocker addon.
  4. Visit The Pirate Bay using Tor Really Private Browsing: An Unofficial User’s Guide to Tor Really Private Browsing: An Unofficial User’s Guide to Tor Tor provides truly anonymous and untraceable browsing and messaging, as well as access to the so called “Deep Web”. Tor can’t plausibly be broken by any organization on the planet. Read More (or any other privacy-focused browser that uses script blockers 4 Anonymous Web Browsers That Are Completely Private 4 Anonymous Web Browsers That Are Completely Private A good way to protect your information on the web is to surf anonymously. Google Chrome’s Incognito mode can help to an extent, but you should also look at the following web browsers. Read More ).

Adding to the well-known script blockers are a generation of browser extensions specifically designed to block popular crypto-mining scripts using your CPU power. Both minerBlock and No Coin are available for Google Chrome. Of course, if you actually want to allow certain sites to use your CPU power, both extensions have a whitelist feature. Better yet, the code for both extensions is available on GitHub, too.

Consent or Not

It really does come down to consent. Trade your privacy for advertisements, or your CPU power for cryptocurrency. The guys over at The Register ran some extremely loose numbers. Check them out. Their loose estimate shows a whopping $123,000 revenue per month.

As they say on the site, they’re “willing to be way off the mark.” They likely are. But if enough users contribute computing power, The Pirate Bay administrators will end up with a significant amount of Monero. And doing it without permission is well… borderline malware.

But before everyone condemns The Pirate Bay (and here are some alternatives Replace The Pirate Bay With These Torrent Alternatives Replace The Pirate Bay With These Torrent Alternatives The Pirate Bay shut shop. But there are lots of alternatives out there. You just need to know where to look. Here are the top six torrent sites other than The Pirate Bay. Read More if you have), let’s remember that they’re not first torrent-focused service to try and profit from cryptomining through their users. uTorrent, anyone?

Will you ditch The Pirate Bay? Or should they just make the Monero-mining opt-in? What are your thoughts on JavaScript cryptomining? Let us know your thoughts below!

Explore more about: Cryptocurrency, Online Security.

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  1. Borislav
    December 5, 2017 at 8:34 pm

    If the website is notifying me as soon as i visit it. I'm comfortable with it, then it’s no harm. Another point that you must take into consideration is the mining load that your CPU would bear. A website should also let me know how much processing power does it intend to utilize.
    In case you’re willing to support your favorite website via this alternative source of revenue and they are being honest about their practices, things are fine for me.

    • Oscar
      April 5, 2018 at 1:14 pm

      I agree, but I do have a question, when you leave the site does the program stop working or does it stay in your cpu.