How to Prevent Cryptojacking

August 07, 2022 - 8 min read

This practice, known as “cryptojacking,” involves the illegal use of a computer, tablet, mobile phone, or other Internet-connected devices to mine for bitcoin and other cryptocurrencies. 

Cryptojacking is a threat that has become increasingly popular recently, especially in 2017 and 2018. Malicious crypto mining was the most frequently detected threat as of February 2018, up from the ninth in September 2017. In October of last year, it was proposed that cryptojacking would become the next big security issue. Instead, there was a fourfold increase in the detection of Android-based cryptojacking malware in the first three months of 2018.

What is cryptojacking?

Cryptojacking is a cybercrime in which another party uses computing resources to mine bitcoin or cryptocurrencies. It is also known as malicious crypto mining, enabling hackers to mine bitcoin without paying for power, hardware, or other mining resources.

Typically, cryptojacking malware attacks devices via regular phishing methods. It can also embed itself in websites and execute in the victim’s web browser when they visit those websites. Cryptojackers target personal computers, laptops, mobile devices, servers, and cloud-based infrastructures. They target everyone from ordinary people to international government entities.

Cryptojacking is a workaround for bitcoin miners who prefer not to utilize their resources to mine. The core concept of cryptojacking is that hackers use commercial and personal computer and device resources to mine cryptocurrency on their behalf. Using these compromised machines, cybercriminals siphon the currency they earn or steal into their digital wallet. As a result, the CPU performance of these infected systems is slowed, and more energy is required for processing.

How Does It Work?

To mine cryptocurrency, cryptojacking employs JavaScript scripts to run on a website. These programs mine cryptocurrency. It is unnecessary to install JavaScript to begin mining because most internet users already have it installed. In point of fact, due to the negligible amount of computing power that is “taken,” the user is quite unlikely to observe any appreciable decline in the computer’s overall performance. It is only when numerous events of the script are running simultaneously, such as when the user has multiple browser windows open at the same time, that the user may perceive a degraded computer response. In addition, the processor’s temperature will emit a significant amount of heat, which is another sign that a device’s security may have been breached.

Not only does cryptojacking include the theft of computer resources, but it also results in a drain on battery power and energy, both of which are paid for by the victim, unaware of what is happening. Last but not least, the lifespan of computer hardware will undoubtedly be shortened if it is subjected to excessive amounts of use and is overclocked.

The practice known as “cryptojacking” can take place in several different ways. Using malicious emails that contain code that can install cryptocurrency mining software on a computer is one of the more common methods. Phishing techniques are used to accomplish this goal. The victim receives an email that appears to contain no malicious content and either a link or an attachment. When clicked, the crypto mining script or extension is downloaded onto the computer. This triggers the execution of a piece of code. After that, the script is executed covertly in the background without the victim’s knowledge.

The term for this type of miner is “web browser miner.” Hackers use this technique to mine cryptocurrency by inserting a script that mines cryptocurrency onto a website or an advertisement that is placed on many websites. The script will automatically run if the victim visits the infected website or if the malicious ad appears in the victim’s browser. Both of these scenarios are considered successful executions. Using this approach, no malicious malware will be left behind on the victim’s PC.

How to detect cryptojacking

You might detect some symptoms, just like with any malicious software infection.

  • Cryptojacking symptoms are indicated by slow response time. Unexpectedly high processor utilization is one of the symptoms of cryptojacking. Other symptoms include overheating your device, poor battery efficiency, and poor performance of your machine overall. If your system is running slowly, crashing frequently, or displaying a version far below average, you should look for potential issues as soon as possible. Another potential clue is that your battery dies quicker than usual, which is another potential clue.
  • Overheating the process of cryptojacking requires a lot of resources and can cause computers and other electronic equipment to overheat. This could potentially cause damage to the computers or limit their lives. For example, suppose the fan on your laptop or computer is operating faster than usual. This could indicate that a cryptojacking script or website is causing the device to overheat. As a result, the fan operates faster to prevent the device from melting or catching fire.
  • If you are visiting a website with very little or no media content and you see that the amount of CPU time you are using has increased, this could hint that cryptojacking scripts are being run on the page. Checking the utilization of your device’s central processing unit (CPU) through either the Activity Monitor or the Task Manager is an effective method for testing for cryptojacking. Keep in mind, however, that the processes may conceal themselves or disguise themselves as something legal to prevent you from ceasing the abusive behavior. Additionally, while your computer is operating at its maximum capacity, it will operate very slowly, making it more difficult to fix any issues that may arise.
  • Implement monitoring in the cloud and runtime security for containers. Additional visibility into cloud settings that illegal crypto miners may impact can be provided by evolving techniques such as cloud monitoring and container runtime security scanning. Cloud service companies are integrating this kind of visibility into their offerings, albeit occasionally in add-ons. For instance, Google Cloud updated its Security Command Center earlier this year to incorporate what it refers to as its Virtual Machine Threat Detection (VMTD), which is designed to pick up on indicators of crypto mining in the cloud in addition to other cloud threats.

Methods used for Cryptojacking

Downloading malware that executes crypto mining scripts, hijacking IT infrastructure, and accessing cloud services are the three primary methods that cryptojackers employ to mine cryptocurrency in a harmful manner. Cryptojackers are also known as crypto miners.

  1. File-Based Cryptojacking

The file-based form of cryptojacking involves downloading and executing malicious software as an executable file, which then distributes a crypto mining script throughout the IT infrastructure. Using malicious emails is one of the most common methods via which cryptojacking can occur. 

An email is sent out with a link or attachment that appears legitimate but is malicious. When a user clicks on the extension or the link, the code downloads the crypto mining script into the machine. This happens when the user interacts with malicious content. This script runs in the background, unseen by the user, and does its tasks.

  1. Browser-Based Cryptojacking

Attacks such as cryptojacking can happen right within a user’s web browser and use the victim’s computer equipment to mine cryptocurrencies. Hackers will first construct a crypto mining script in a programming language of their choosing, and then they will implant that script into a variety of websites. 

The script is executed immediately once the code has been successfully downloaded onto the user’s machine. These malicious scripts can be inserted into advertisements as well as plugins for WordPress that are out of date and insecure. A supply chain attack is another method that can be used to commit cryptojacking. In this assault, crypto mining code is inserted into JavaScript libraries.

  1. Cloud Cryptojacking

Hackers who utilize cloud cryptojacking look through a company’s files and code in search of API keys to access the organization’s cloud services. Once they have gained access, hackers will immediately begin to steal infinite CPU resources for crypto mining, resulting in a significant increase in account expenses. Additionally, hackers can significantly speed up their cryptojacking operations to illicitly mine for cryptocurrency if they utilize this strategy.

How to Prevent Cryptojacking

Due to its evolution into a multi-vector attack that spans endpoint, server, and cloud resources, preventing cryptojacking requires a coordinated and comprehensive defense strategy. The following steps can help prevent enterprise resources from being exploited by cryptojacking.

  1. Patch and secure servers

Typically, cryptojammers seek the lowest-hanging fruit they can stealthily harvest; this includes scanning for publicly accessible servers with older vulnerabilities. However, basic server hardening techniques such as patching, disabling unnecessary services, and eliminating external footprints can significantly reduce the danger of server-based assaults.

  1. Instruct your IT staff

IT personnel should be trained to recognize and comprehend cryptojacking. In addition, they must be aware of any early warning signs of an attack and be prepared to investigate immediately.

  1. Educate your staff

IT teams rely on employees to report overheated or sluggish computers. Employees must understand cyber security to avoid clicking on links in emails that may contain cryptojacking code and to only download files from known links.

  1. Disable JavaScript

By disabling JavaScript when online, you can prevent cryptojacking code from infecting your machine. Keep in mind that disabling JavaScript will block many of the functions you need when browsing. There are several ways to disable Javascript, including using a free extension such as Quick Javascript Switcher. You can also utilize a specific feature of the Tor browser to prevent cryptojacking.

  1. Utilize browser extensions meant to prevent cryptojacking. 

Cryptojacking scripts are frequently implemented in web browsers. You can block cryptojackers across the web with specialized browser extensions, such as minerBlock, No Coin, and Anti Miner. They can be installed as extensions in several popular web browsers.

  1. Install ad blockers

Since cryptojacking scripts are frequently distributed through internet advertisements, installing an ad blocker can prevent them. Ad-blocking software, such as AdBlocker Plus, can detect and block cryptojacking codes.

  1. Employ robust endpoint protection

The cornerstone of this is deploying endpoint protection and anti-malware that can detect crypto miners, as well as maintaining web filters up-to-date and managing browser extensions to reduce the chance of browser-based script execution. Ideally, organizations should seek endpoint protection technologies extending to servers and beyond.

Final Thoughts

Cryptojacking is one of the most significant risks to mobile security that you should take seriously. Fortunately, it is also one of the most accessible mobile security threats since it can be stopped with vigilance and simple browser extensions. However, it can be challenging to detect the intrusion manually, whether locally on your PC or through the browser, after it has already occurred. Cryptojacking can happen either way. Similarly, tracking down the source of the excessive use of the CPU might be challenging. Processes may be concealing themselves or disguising themselves as something legal to prevent you from putting a stop to the abuse. By utilizing an MDR service provider, you will be able to detect attacks of this nature because this provider will see an increase in activity that is not typical for your networks.

To level up and gain a deeper knowledge of all things related to the future of the cryptocurrency industry, check out the latest content in the Supra Academy section.


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