Cryptojacking
The unauthorized use of someone else's computer, server, or device to mine cryptocurrency without their knowledge or consent, typically through malware or a compromised website.
Cryptojacking is the unauthorized use of a victim's computing resources — typically CPU or GPU processing power — to mine cryptocurrency on an attacker's behalf, without the victim's knowledge or consent. It's commonly delivered through malware installed on a compromised device, or through malicious JavaScript embedded in a compromised website that runs mining code directly in a visitor's browser for as long as they keep the page open.
Unlike many crypto-related attacks, cryptojacking doesn't directly steal funds or private keys from the victim; instead, it quietly steals computing resources and electricity, often going unnoticed for extended periods beyond symptoms like a device running unusually hot, slow, or with abnormally high resource usage. Because cryptojacking primarily targets coins that remain profitable to mine on ordinary consumer hardware (such as GPU-mineable or CPU-mineable coins), it has become less common against networks that have shifted toward specialized mining hardware or proof-of-stake, where ordinary compromised devices can no longer contribute meaningful mining power.
Examples
- A compromised website running hidden cryptojacking JavaScript can quietly mine cryptocurrency using a visitor's CPU for as long as they keep the browser tab open.
- Unlike phishing or malware that steals private keys directly, cryptojacking instead quietly steals a victim's computing resources and electricity to mine on the attacker's behalf.