As the adoption of cryptocurrencies continues to expand, so do the associated security threats. Among the growing list of cybercrimes, cryptojacking has emerged as a particularly stealthy and damaging tactic. Often unnoticed by victims, cryptojacking allows malicious actors to exploit computing resources for unauthorized cryptocurrency mining.
In this article, we’ll examine what cryptojacking is, how it works, how to detect it, and what individuals and organizations can do to protect themselves.
Cryptojacking is the unauthorized use of someone’s computing device, such as a PC, smartphone, server, or IoT hardware, to mine cryptocurrency. The term combines “crypto,” referring to cryptocurrency, and “hijacking,” indicating the covert takeover of computing resources.
Unlike traditional forms of cybercrime, cryptojacking does not steal sensitive data or damage systems directly. Instead, it leeches processing power, resulting in reduced device performance, higher electricity usage, increased wear and tear, and potential long-term hardware damage.
How Cryptojacking Works?
Cryptojacking typically occurs in one of two ways:
1. Malware-Based Cryptojacking
This method involves tricking the victim into downloading malicious software. It may be disguised as a legitimate application, attachment, or browser extension. Once installed, the malware silently runs a mining script in the background, continuously using the device’s CPU or GPU to mine cryptocurrencies such as Monero (XMR), which is favored for its privacy and mining algorithm suitability.
2. Browser-Based (Drive-By) Cryptojacking
In this form, no malware installation is necessary. Instead, malicious JavaScript code is embedded into websites or online advertisements. When a user visits the infected site, the mining script begins executing in their web browser, harnessing their processing power for as long as the page remains open.
Because both forms of cryptojacking are designed to operate invisibly, users are often unaware that their systems are being exploited.
Why Cybercriminals Use Cryptojacking
The appeal of cryptojacking lies in its low-risk, high-reward nature:
- Anonymity: Cryptojacking operations are difficult to trace, especially when mining privacy coins.
- Scale: A single attacker can infect thousands of devices and combine their computing power to generate substantial mining revenue.
- Persistence: Cryptojacking scripts are designed to remain undetected for long periods, providing a steady income stream to the attacker.
For cybercriminals, this makes cryptojacking more attractive than ransomware or data theft, as it doesn’t trigger the same level of urgency or scrutiny from victims.
Consequences of Cryptojacking
While cryptojacking may seem less dangerous than other cyber threats, its impact should not be underestimated:
- Reduced Performance: Devices become noticeably slower, affecting productivity and user experience.
- Increased Operational Costs: Continuous mining leads to higher energy consumption and utility bills.
- Hardware Degradation: Prolonged high CPU/GPU usage can shorten device lifespan or cause overheating.
- Network Strain: In corporate environments, cryptojacking can strain IT infrastructure and reduce overall network efficiency.
- Security Risks: Systems infected with mining malware may be vulnerable to other types of cyberattacks.
These effects can accumulate significantly, especially in business settings with multiple compromised systems.
How to Detect Cryptojacking?
Because cryptojacking is designed to operate quietly, detection can be challenging. However, there are several warning signs:
- Unusual CPU or GPU Usage: A sudden spike in processing power, even when no heavy applications are running.
- Device Overheating: Systems become unusually hot, or fans run at maximum speed.
- Sluggish Performance: Applications take longer to open, and overall system responsiveness declines.
- Browser Slowdowns: Pages lag or crash more frequently.
- Battery Drain (on mobile devices): Rapid battery depletion without obvious cause.
Monitoring tools, antivirus software, and task managers can help identify suspicious processes or scripts running in the background.
Preventing Cryptojacking
Prevention is key to protecting against cryptojacking. Here are several best practices:
1. Keep Software Updated
Ensure all operating systems, browsers, and applications are up to date with the latest security patches to prevent exploitation of known vulnerabilities.
2. Use Reliable Security Software
Install and regularly update reputable antivirus and anti-malware solutions that can detect and block mining scripts and malicious downloads.
3. Block JavaScript Mining Scripts
Browser extensions like NoCoin, MinerBlock, or built-in ad blockers can prevent mining scripts from running in the browser.
4. Educate Employees and Users
Training users to recognize phishing attempts, suspicious downloads, and unusual system behavior is essential, especially in corporate environments.
5. Monitor System Performance
Implement monitoring tools that provide real-time analytics on CPU/GPU usage and network activity. Unusual patterns can indicate a cryptojacking attempt.
