What is Cryptojacking and How to Protect Yourself?

In the era of digital technology, cybercriminals increasingly resort to sophisticated methods to make a profit. One such method — cryptojacking — turns computers, smartphones, and even servers into “digital slaves” mining cryptocurrency for third parties. The problem has become so widespread that it’s now being called a new form of digital piracy.

So what is cryptojacking, how can you recognize it, and most importantly, how can you protect yourself? Let’s break it down.

What is Cryptojacking?

Cryptojacking is the hidden or unauthorized mining of cryptocurrency (most often Monero) using someone else’s device resources. Malicious code is installed on a user’s device and begins using CPU or GPU power to mine cryptocurrency — usually without the owner’s knowledge.

Example: you open a website, and your laptop starts overheating, the fan runs at full speed, and the battery drains rapidly. The site may contain a cryptojacking script.

How Cryptojacking Works

There are two main methods:

1. Browser-based cryptojacking:
2. Malicious JavaScript is embedded in web pages. While the user is on the site, their device mines cryptocurrency.
3. Malware-based:
4. Attackers distribute infected programs or phishing links. Once installed, the miner runs in the background 24/7.

Signs of Cryptojacking

Watch out if:

• Your device overheats suddenly without heavy usage.
• CPU usage hits 80–100% with no active tasks.
• Battery drains quickly.
• Unknown processes appear in Task Manager or Activity Monitor.
• Browser freezes on certain websites.

How to Protect Yourself from Cryptojacking

1. Keep everything updated — operating system, browser, antivirus. Vulnerabilities are often exploited.
2. Install mining blockers — browser extensions like No Coin, MinerBlock, or uBlock Origin (with extra filters).
3. Monitor CPU activity — use Activity Monitor on macOS or Task Manager on Windows.
4. Use reliable antivirus software — Malwarebytes, Bitdefender, Kaspersky, etc., can detect hidden miners.
5. Be cautious installing software — download only from official sources.
6. Restrict JavaScript on unknown sites — extensions like NoScript or strict privacy mode help.

If Your Device is Already Infected:

• Disconnect from the internet to cut off the miner.
• Run a full antivirus scan.
• Remove suspicious programs and extensions.
• Reset your browser to factory settings.
• Update all passwords.
• In extreme cases, reinstall the operating system.

Cryptojacking is a new reality of digital threats. It may seem harmless since it doesn’t directly encrypt or steal data like ransomware, but it still damages your device, drains resources, and compromises security.

The key rule — vigilance. Monitor how your device operates. If something seems off, it probably is.