Home » Cryptojacking: Detection & Prevention Tips

Cryptojacking: Detection & Prevention Tips

December 23, 2023 • César Daniel Barreto

Cryptojacking is a cybercrime where cybercriminals exploit people’s devices (like computers, smartphones,
and servers) without permission to mine cryptocurrency, a digital or virtual money represented by tokens or
“coins” like Bitcoin. Unlike other cybercrimes, cryptojacking aims to stay hidden from its victims.
Cryptocurrency operates on a blockchain, a distributed database that records transactions.
Mining cryptocurrency, a process essential for creating new blocks in the blockchain, demands significant
computing power and electricity. Miners, who trade computing resources for cryptocurrency, often use
dedicated computer rigs for these complex mathematical calculations. Large cryptocurrencies, such as Bitcoin,
require substantial energy for mining, with the Bitcoin network consuming over 73TWh annually.

The Process of Cryptojacking

Cryptojacking attacks, where hackers use target computers to mine cryptocurrencies covertly, employ various
strategies. They may use these methods individually or in combination for more effective attacks.

  • Download Method: In this approach, attackers trick victims into downloading crypto mining code onto
    their devices. This usually involves social engineering techniques like phishing, where victims receive
    seemingly legitimate emails urging them to click on a link. This link then executes a malicious code that
    installs the cryptomining script, which operates silently in the background as the user continues their work.
  • Injection Method: Another common tactic is script injection. Here, the attacker embeds a cryptomining
    script into an advertisement or website. When a user visits the infected website or views the ad, the script
    automatically executes. Unlike the download method, this strategy does not store any code on the victim’s
    computer. Instead, it runs complex mathematical problems directly through the browser, sending the
    results back to a server under the hacker’s control.
  • Hybrid Attacks: Attackers often combine download and injection methods to increase their impact. For
    example, in a network of devices mining cryptocurrency for an attacker, a portion might be mining through
    downloaded code on the machines, while the majority might be doing so through their web browsers.
  • Browser-Based Cryptojacking: Browser-based cryptojacking is particularly insidious as it allows the
    mining process to happen entirely through the web browser without any code stored on the victim’s

The Spread of Cryptomining Scripts

Cryptomining scripts can have worm-like capabilities, allowing them to spread across servers and devices
within a targeted network. This propagation makes them challenging to isolate and remove, as maintaining a
presence on a network is financially beneficial for a cryptojacker.
To enhance their ability to infect various systems, crypto mining scripts may include multiple versions tailored
to exploit different vulnerabilities in network protocols. In some cases, the script will attempt to download and
execute these different versions sequentially until one successfully infiltrates the system.

Identifying Cryptojacking Symptoms

Performance Degradation

A noticeable decline in the performance of electronic devices, including PCs, laptops, tablets, and
smartphones, is a common indicator of cryptojacking. A slowdown in processing speeds should prompt your
staff to alert the IT department.

Overheating Issues

Cryptojacking is resource-intensive and can lead to overheating in computing devices. This not only risks
damage to the devices but may also reduce their overall lifespan. Continuous operation of cooling fans beyond
normal usage can also signify overheating due to cryptojacking.

Monitoring CPU Usage

Keep track of CPU usage through tools like Activity Monitor or Task Manager. An unusual increase in CPU load,
especially when browsing websites with minimal media content, could suggest the presence of crypto mining

Website Vigilance

Cybercriminals often target websites to implant crypto mining code. Regularly inspect your websites for any
unauthorized changes to web pages or files on the server. Early detection can prevent cryptojacking from
taking hold in your systems.

Rapid Battery Depletion

Devices affected by cryptojacking may exhibit faster battery drainage than usual, a consequence of the
increased processing power being used for cryptomining.

Malware Scans

Cryptomining malware, such as CryptoLocker, not only uses system resources like cryptojacking scripts but
can also encrypt files and demand a Bitcoin ransom. Regular malware scans using your security software, or
tools like PowerShell, can help in detecting these malicious programs and thwarting cryptojacking attacks.

Cryptojacking Prevention

There are several proactive steps you can take to safeguard your network and crypto-assets:

Train Your IT Team

Ensure your IT staff is well-trained in recognizing the early signs of cryptojacking. They should be equipped to
quickly investigate any potential attacks.

Employee Education

Employees play a crucial role in identifying cryptojacking. They should be informed about the importance of
cybersecurity and trained to report any signs of compromised systems, such as overheating or slow
performance. Additionally, they need to be cautious about clicking on email links and should only download
from trusted sources to avoid inadvertently introducing cryptojacking code.

Utilize Anti-Cryptomining Browser Extensions

As cryptojacking scripts are often executed through web browsers, it’s beneficial to use browser extensions
like No Coin, minerBlock, or Anti Miner. These tools are specifically designed to block crypto miners across the

Implement Ad-Blockers

Cryptojacking scripts frequently hide within web advertisements. By using ad-blockers, you can both block
and detect malicious crypto mining code, adding an extra layer of protection against these attacks.

Disabling JavaScript

Consider disabling JavaScript while browsing online to prevent cryptojacking scripts from infiltrating your
organization’s computers. However, be aware that this will also restrict some functionalities essential for
By integrating these strategies into your cybersecurity approach, you can significantly enhance your defenses
against the increasingly common threat of cryptojacking.

Invest in a Robust Cybersecurity Program

Implementing a comprehensive cybersecurity solutions is crucial. Such programs
offer broad-spectrum threat detection, including protection against cryptojacking malware. Regularly updating
your operating system
and applications, particularly web browsers, is also a key practice in safeguarding your

Cybercriminals continually evolve their tactics, so staying informed about the latest cryptojacking methods is
vital. Proactively monitoring cybersecurity news can help you recognize and mitigate these threats promptly.

Utilize Cryptojacking-Blocking Browser Extensions

Employ browser extensions specifically designed to thwart cryptojacking, such as minerBlock, No Coin, and
Anti Miner. These extensions are compatible with many popular browsers and can effectively prevent
cryptojackers from executing scripts.

Regularly Update Your Security Software

Ensure that all your devices are equipped with updated and trusted cybersecurity or internet security solutions.

By combining these strategies with general cybersecurity best practices, you can significantly reduce the risk
of falling victim to cryptojacking and safeguard your network and devices effectively.

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César Daniel Barreto

César Daniel Barreto is an esteemed cybersecurity writer and expert, known for his in-depth knowledge and ability to simplify complex cyber security topics. With extensive experience in network security and data protection, he regularly contributes insightful articles and analysis on the latest cybersecurity trends, educating both professionals and the public.