How a webpage can turn processor cycles into cryptocurrency
A browser normally uses your processor to lay out text, run animations, and respond to clicks. A mining script can add a different job: repeatedly hashing data—running it through a calculation that produces a short digital result—until it finds a result that meets the cryptocurrency network’s rules. In proof-of-work systems, that result helps verify transactions and can earn a reward for the miner.
The calculations are repetitive but demanding. A script can ask a computer’s processor to perform them while the page remains open, often without making the activity obvious on screen. The website operator or whoever placed the script gets the potential reward; the visitor supplies the processing time and electricity.
Why the fan is the giveaway
When a processor works harder, it uses more power and produces more heat. The computer’s cooling system responds by spinning its fan faster, so a quiet reading session can suddenly become noisy. The same extra workload may make the page feel sluggish or drain a laptop battery sooner.
A loud fan alone does not prove that a page is mining—many ordinary tasks can heat a device. But if the fan settles after a particular tab closes, that tab may have been consuming unusual resources. The practical cost is immediate: while the page is open, some of your computer’s capacity is doing work for someone else.
