Cryptojacking, also referred to as “malicious cryptocurrency mining,” is a form of fraudulent activity done via the Internet with the goal of using someone else’s laptop or personal computer to obtain digital currencies—which can be bitcoin (BTC) or any of the thousands of others—through mining.

To put it simply, these hackers, called cryptojackers, hack your device and use its computational powers to mine cryptocurrencies. So why do they do it? The main objective of cryptojacking, as we’ve mentioned previously, is to mine cryptocurrencies. To further understand this activity, let’s first have a quick look at cryptocurrency mining.

In order to engage in the process of acquiring digital currencies, a lot of resources are needed: high-powered computers, equipment like mining rigs, enough electrical supply, a stable Internet connection, and specialized software. For a more in-depth explanation, check out our blog posts about Bitcoin mining and Ethereum mining.

What cryptojackers aim to do is to mine cryptocurrencies using the computational powers or computing resources of their victim’s device or equipment. By doing this, hackers can get away with expensive resources needed to mine virtual currencies.

These hackers can obtain the victim’s computing resources without their knowledge and consent. Another alarming fact is that cryptojacking is not limited to laptops. Apart from targeting personal computers, cryptojackers can perform this malicious activity on target users’ smartphones, tablets, other home devices that are connected to the Internet, and servers as well.

Types of cryptojacking attacks

Cryptojackers usually make their attacks in two ways. The first is through malware scripts, and the second is through the in-browser JavaScript code.

Malware scripts

This attack is similar to phishing scams that use malicious links that redirect to compromised pages that are able to obtain sensitive information when clicked. In cryptojacking done through malware scripts, a link that contains malware automatically downloads a malicious code and installs it to the victim’s laptop or device when clicked. After successful installation, cryptojackers can start the mining process on the victim’s device.

Typically, malware works by harming and destroying a victim’s computer once it successfully enters the operating system. However, cryptojacking through malware scripts works differently.

Since the hackers need the victim’s equipment and its computing powers to run crypto mining operations, the malware will spare the compromised device. It will not harm the computer so it can mine cryptocurrencies in the long run.

In-browser JavaScript code

This attack, often called “drive-by cryptocurrency mining,” works by targeting computers through embedding a compromised and malicious JavaScript code into a web page. The device used to browse or visit the implanted or embedded website can quickly become cryptojacked or used as a tool for illicit cryptocurrency mining.

Some articles in the crypto sphere note that not every in-browser cryptocurrency mining method is considered malicious, as it was reportedly used to monetize pages through digital currencies. Among the said industries include those in gaming and content. 

How to detect cryptojacking

While this malicious activity works very discreetly and without the victim knowing, there are some visible signs that can tell you whether or not your device is being cryptojacked.

  • Spike in CPU usage. Check your computer’s performance. One good indicator is if you notice an increase in the usage of your computer’s Central Processing Unit (CPU) while visiting websites that don’t contain a lot of media content. If this happens to your device, it is more likely that your device is infected by cryptojacking malware.
  • Unusual slow response. Crypto mining runs complex operations and requires much computing resources from your equipment. Because of this, you will notice an uncommon lagged response from your computer, even with its most basic functions.
  • Device overheating. Since there are additional and complex operations running in the background with cryptojacking, you may notice a slight change in your computer’s temperature.

How to prevent cryptojacking

Now that you have the indicators that will help you know if your device is compromised, let’s learn the practical ways to prevent your device from being a tool for hackers’ illicit crypto mining processes.

  • Download and install an ad-blocker. This is one of the most common ways to prevent being a victim of cryptojacking. Having an ad-blocker installed on your browser will keep your device from clicking or opening compromised and malicious codes that are embedded in online ads. Ad-blockers are also considered a good choice if you’re looking for device protection as it is deemed for detecting cryptocurrency mining scripts.
  • Install anti-cryptocurrency mining extensions. Some folks are not fans of having extensions on their web browsers. However, if you think you are susceptible to cryptojacking and other cryptocurrency-related frauds online, you can try getting some plug-ins for an added layer of security. There are a lot of this type of software you can install for free, so make sure you check them out and pick one that works effectively for you.
  • Keep your web filtering tools up-to-date. Constantly updating your filtering tools enables the same or even higher levels of protection while browsing.
  • Be aware of malicious links and emails. Phishing scams and other fraudulent activities anchored through malicious links are prevalent in the crypto world. So it is crucial to have a proper understanding of what these are and how to avoid them. If you’ve received a suspicious email, it is suggested that you do not click it right away to prevent malware infection from happening. 
  • Keep yourself updated about cryptojacking incidents, news, and trends. Be sure to always check all the latest news related to this illicit activity. Knowing the latest news and reports about cryptojacking will surely help give you an idea of how it advances and how you can get away from it.