Cryptojacking
In short: Cryptojacking is using a computer to mine cryptocurrency without the user's consent. The attacker collects the mining rewards, while the victim pays for…
Cryptojacking is using a computer to mine cryptocurrency without the user's consent. The attacker collects the mining rewards, while the victim pays for the electricity, the lost performance, and the extra wear on the hardware.
Why it matters
Cryptojacking is quieter than most attacks, so it can run unnoticed for a long time, and attackers usually choose coins that can be mined efficiently on ordinary processors. It typically arrives through malware on a computer or phone, a mining script hidden in a website that runs while the page is open, or stolen cloud credentials used to start mining servers that the account owner ends up paying for. Warning signs include a device that is slow or hot while idle, fans running constantly, an unknown process using most of the CPU, and unexpected jumps in electricity or cloud bills. Regular updates, reputable security software, script blocking in the browser, and well-protected cloud keys all reduce the risk.
Example
An office worker notices that a laptop fan never stops, even with no programs open. The IT team finds a hidden process that uses most of the processor to mine a cryptocurrency and send the rewards to an unknown wallet. After the malware is removed, the software is updated, and the exposed passwords are changed, the laptop runs normally again.