Your computer’s fan is spinning like crazy. You feel like your laptop is overworking all the time, and soon it’s going to go “kaboom.” It may be a cryptojacking attack.

The subject of cryptocurrency has become controversial in recent years as these virtual assets continue to achieve popularity. Consequently, hackers have come up with various fraud schemes to take advantage of digital currencies. Such is the case of cryptojacking.

Cryptojacking is a form of illegal cryptocurrency mining, where hackers take over servers, computers, mobile phones, and even common devices such as printers.

The bad actors use the hijacked CPU’s processing power for solving mathematical calculations to decode cryptocurrency hashes and thus generate money.

The problem is that detecting a cryptojacking attack in your computer is not always easy as the mining software is often well hidden and easily confused with other applications. Hackers can also throttle how much power they take from the computer, so you may not even notice the attack.

virus-computer (cryptojacking)

How does Cryptojacking Happen?

Malicious software can enter your computer either through a download or by visiting an infected web page. Once installed, the software uses legitimate Windows process names to go unnoticed and steal performance from the CPU for cryptocurrency mining purposes.

“Cisco’s Threat Analysis, which processes 620 billion global DNS requests daily, reported that cryptojacking affected more than 69% of customers in 2020. (Source)”

By piggybacking on other people’s computer power, cryptojacking gives hackers the ability to generate cryptocurrency without incurring costs.

How to detect cryptojacking

How to Detect It?

One main symptom of cryptojacking is a decrease in the performance of the computer or device. If you notice that it’s running slower than usual or that it stops responding, don’t take it as a minor issue.

Another indication that something may be wrong is that your battery lasts less than usual. This may not be a problem with your battery. 

Like any intensive process, crypto mining can cause the device to overheat. Extreme temperatures can cause equipment damage or shorten the device’s lifespan. If you notice that your computer’s fan is spinning at full speed, it could be that the temperature has risen because of a crypto mining script running in the background.

The problem with cryptojacking goes beyond a single device. Crypto mining scripts behave like “virtual worms.” Once they have access to a network, they try to infect as many devices and servers as possible.

This problem is more challenging to identify and eliminate. Some scripts also scan the victim’s device to determine if he had already been infected by other mining software. If this is the case, they will disable the competing application.

How to Prevent Cryptojacking?

How to Prevent Cryptojacking?

Protecting yourself from cryptojacking is not as simple as protecting yourself from other malware attacks. Although you can (and should) take into account the most common security practices, here are essential tips: 

Install an antivirus solution on your computer that includes endpoint protection and DNS/Web filtering. 

  • Do not install software from unofficial sites.
  • Be careful with the extensions you add to your browser.
  • Look over links you open; sometimes, a legitimate website can be compromised and infect your computer without you being aware.
  • Install extensions such as Minerblock that block all types of crypto miners on the web. 
  • Be careful with websites asking you for authorizations.
  • Use a Network Intrusion Detection System (NIDS) inside your company to detect cryptojacking on servers, workstations, and network devices. More on this.
  • In addition to this, some ad blockers like Adblock Plus and uBlock Origin include specific lists to block mining.

Whatever options you use, I recommend that you also monitor your computer’s resource consumption from time to time, especially when you notice changes in performance, speed, or that fans suddenly begin to make lots of noise.

In an ever-changing threat landscape, staying safe from the latest dangers like cryptojacking is a full-time job. I hope the information in this article is helpful to you. Feel free to reach out if you have comments or questions.


Dan Duran
Rhyno Cybersecurity


Rhyno delivers a range of activities that combine to fully protect your infrastructure and data from cybercriminals, anywhere and everywhere, 24/7/365.


About Rhyno Cybersecurity Services

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Our products and services are robust, innovative, and cost-effective. Underpinned by our 24x7x365 Security Operations Centre (SOC), our experts ensure you have access to cybersecurity expertise when you need it the most.