What is Cryptojacking?

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Summary - What is Cryptojacking? How to Detect and Prevent it

Cryptojacking is a type of cybercrime where hackers use your computer to mine cryptocurrency. They do this because while cryptomining can be lucrative it’s also taxing on a computer.

This is why it’s so important to detect cryptojacking as soon as possible. Some indications of cryptojacking include an underperforming computer, an overheating device, and increased use of the CPU.

Since new forms of this cybercrime don’t leave a trace on your computer, it can be difficult to detect or prevent cryptojacking. Learn more about how you can defend yourself by reading the article below.

With the arrival of cryptocurrencies came a new type of cybercrime called cryptojacking. You may be asking yourself, what is cryptojacking, and how does the threat of it affect me? Cryptojacking is when someone uses your computer online to mine cryptocurrency without your knowledge.

In this article, we’re going to explain what cryptojacking is, how to detect and prevent cryptojacking, as well as what you should do if it happens to you or someone you know.

To answer the question, what is cryptojacking, you need to understand why people mine for cryptocurrencies and how the cryptocurrency mining process works.

What is Cryptomining?

Bitcoin MinerFor you to best understand cryptomining you need to have some general knowledge about digital blockchain technology. In this article, we’ll focus on Bitcoin mining since this is the most common type of cryptocurrency. In many ways, blockchain is the digital ledger that all cryptocurrency transactions are registered. You’ll have a copy of this blockchain if you have a system with crypto-software installed on it. Just remember that not all cryptocurrencies are based on blockchain technology.

How Do Cryptomining Systems Work?

To help you understand how mining cryptocurrencies works, let’s look at Bitcoin transactions. A cryptominer verifies a crypto transaction. The miner earns money by verifying one “block” of transactions. One of these blocks equals 1 MB of data. To earn Bitcoin could mean the users only have to verify a single transaction. On the other hand, this can also mean that the users would have to verify a thousand cryptocurrency transactions. This depends on the complexity and the data of the transactions. When a block is verified by someone it’s added to the digital blockchain.

Another way to look at cryptomining is that in exchange for the verification done by the miner, Bitcoin rewards them with Bitcoin. They can use this to invest or use it for online payments.

The reason miners choose to mine cryptocurrencies is that they want to earn money in the form of cryptocurrency. Bitcoin profits from cryptomining in different two ways. First, by checking all transactions, cryptominers make sure that people don’t abuse the system by spending the same cryptocurrency twice. Second, because miners receive payment in Bitcoin, they’re introduced new cryptocurrency to the network which makes it grow.

What is Cryptojacking?

To mine cryptocurrency, you need special hardware and a lot of computing power, both of which can cost a lot of money to purchase. Many cryptominers want to mine cryptocurrency but aren’t willing to pay the money for the cost of the hardware when it comes to finding resources to mine. This desire to mining cryptocurrency but not pay for the required equipment is why cryptojacking exists. Cryptominers take over someone else’s system online so they can mine. Similar to a botnet, your device is at the disposal of the hacker.

You may think you won’t become a victim of cryptojacking because you don’t have enough computing power but this isn’t the case. Typically, cryptojackers don’t target specific systems. Also, there are many cryptocurrencies that can be mined without a dedicated graphics card or specific hardware. In fact, a cryptocurrency like Monero can be mined by using any CPU.

How Does Cryptojacking Work?

HackerThere are two ways in which cryptojacking hackers can gain access to your hardware’s processing power. These are the most common methods of inserting cryptojacking scripts:

  • The hackers inject a malicious cryptojacking script onto your hardware when you click an illegitimate link. This is often combined with phishing techniques.
  • The hacker places the cryptojacking script onto a popular website so that every computer that visits the site will start cryptomining automatically.

The second method of cryptojacking is very difficult to detect because no digital code is placed on your computer. In this case, the script is run through web browsers instead of on your computer. That’s why most antivirus programs don’t detect this form of cryptojacking which is also known as browser-based mining.

What are the Consequences of Cryptojacking?

Slow computerThe cryptojacking code works in the background of systems without you noticing. Your hardware’s processing power is used to mine cryptocurrency which makes your hardware much slower than usual. You’ll also have someone on your computer without your knowledge which is always dangerous when it comes to your personal data.

How to Detect Cryptojacking

Even though it can be difficult to see whether you’ve been infected by cryptojacking ransomware, there are ways you can check to see if you’re a victim of cryptojacking through malware on your device. The following are the most common indications of whether your devices have been taken over:

Keep an Eye on the Performance of Your Hardware

Since cryptomining slows down computers, this is the easiest way to identify if your computing power has potentially been taken over by malware from cryptojackers. Having a slower computer doesn’t always mean you’re dealing with cryptojacking but it is one indication.

Check Windows Task Manager

Windows Task Manager lets you check whether there’s something suspicious going on with your computer by monitoring the programs running in the background of your computer. You should check your Task Manager to see if there’s something running you don’t recognize. If there’s a program that looks malicious you can stop it from running directly from Task Manager. This is a great way to monitor cryptojacking threats to prevent mining cryptocurrency from happening on your hardware without you knowing.

Use Reliable Antivirus Programs

Downloading antivirus scanners, like Bitdefender, will help you identify cryptomining malware on your hardware. Cryptomining scripts aren’t detected as malware by antivirus programs but if they get on your hardware through phishing techniques they can be detected. This detection is why a reliable antivirus program is critical to protecting your devices from cryptojacking.

Check Your Browser Icon

If cryptojackers are working on your devices you’ll notice that your internet window icon will remain active even if you’ve closed your window.

Check for ‘Strange’ File Names

If you own a website and want to see if it’s been infected by malware, check for filenames such as ccminer.exe. All crypto-related names that don’t look familiar could indicate that your website’s security has been cryptojacked for cryptocurrency mining.

Watch Your Electricity Bills

Not only does cryptojacking malware code slow down your device by using its resources, but it also increases the cost of your electricity bill. This is because so many of your device’s resources are being used consistently. If you notice a spike in your monthly bill, this could be because of cryptomining code using your computing power.

How to Avoid Getting Cryptojacked

Cryptojacking has become almost impossible to protect yourself from online. This is mostly because you don’t have any control over the files that are installed on other websites. Even with this in mind, there are some security steps you can take to ensure your chances of being cryptojacked are as small as possible.

Use an Ad-Blocker

adlock logo smallCryptomining scripts are usually hidden in ads on websites so if you use an ad-blocker you can avoid some forms of cryptojacking. Some ad-blockers, such as Adblock Plus, even have a feature in which they can identify some cryptomining scripts.

Use Special Extensions

Some extensions that detect cryptomining scripts placed by hackers on websites include NoMiner and minerBlock.

Use Antivirus Software

Antivirus software is useful if your computer has already been infected by a cryptojacking script. Just like with regular viruses or malicious code, you can quarantine a script and delete it. On top of that, a lot of antivirus software offers preventative options that can detect cryptomining scripts.

Use a Firewall that is Updated

This is particularly important if your device is part of a larger network of computers that uses a collective firewall. If you think a webpage has a cryptomining script, it’s critical that the network firewall is updated so you and everyone in the network is blocked from visiting this page on their computers through the web. This will protect your network from cryptocurrency miners who want to use your resources without your knowledge.

Disable Javascript

Javascript code is the most common script on any website which is why hackers usually hide cryptomining scripts in Javascript elements. There are several ways to disable Javascript such as using a free extension like Quick Javascript Switcher. You can also use a special feature in the Tor-browser to protect yourself from cryptojacking.

Don’t Fall for Phishing Emails and Messages

These days, cryptojacking usually happens through open tabs in your internet window. That doesn’t mean it can’t happen in other ways such as your system’s security being infected by malware. This mostly happens through malicious links in phishing emails so make sure you never click on links in emails you don’t recognize.

What to Do if You’ve Been Cryptojacked

Don’t panic if you’ve been cryptojacked. If you’ve discovered that there is a cryptomining script on your system you should delete this file as soon as possible. This will prevent cryptocurrency mining from happening on your hardware causing your system’s resources to slow down and compromising your personal data.

If you think there’s a cryptomining code on your computer you should run an antivirus program to scan your drives for any threat. If any files are found in the scan that you don’t recognize you need to delete them as soon as possible.

Browser cryptojacking is a little easier to resolve because all you need to do is close the window. You should also confirm with your Task Manager that there aren’t any processes running that are using a lot of your computer’s resources. If there are processes you don’t recognize you can stop them manually.

Cryptojacking is a misleading type of cybercrime that’s difficult to detect. If you lookout for the signs and use the tips in this article, you’ll limit the chances of being cryptojacked and lower the impact of it if it does happen.

Cryptojacking - Frequently Asked Questions

Check out our FAQ below to read some of the most commonly asked questions about cryptojacking.

Cryptojacking is a method used by cybercriminals to gain access to your computer so they can mine cryptocurrency. They do this because while cryptomining can be lucrative it’s also taxing on the hardware. Cryptojacking lets the cybercriminal use your computer’s resources to mine the cryptocurrency. Read our comprehensive article about cryptojacking to learn more!

Cryptomining is the verification of cryptotransactions with the goal of preventing one cryptocoin or -unit from being spent more than once. Cryptomining makes sure that the system of cryptocurrencies stays honest and free from fraud. People mine crypto because they will be rewarded with cryptocurrency when they do.

There are some signs that can point to cryptojacking:

  • A computer that is much slower than usual
  • An overheating computer or a fan that is much louder than normal
  • Unusually high use of CPU or GPU. You can check these in the Windows Task Manager

The points listed above are only a few of the indications that you’ve been cryptojacked. However, the signs that have to do with the performance and power usage of your computer are the best ways to detect these modern types of cryptojacking. For more information, you can read our article on cryptojacking.

Cryptojacking is a vicious type of cybercrime that you usually don’t notice. But there are some steps that you can take to limit the chance of it happening to you:

  • Use an adblocker
  • Disable Javascript
  • Use special browser extensions that can detect cryptomining scripts, such as NoMiner and minerBlock
Tech writer
Brad is a digital marketing specialist with years of hands-on experience working in the industry. When he's not working, Brad spends his time with his young daughter and wife. Some of his hobbies include video games, reading, writing, and travelling.