What is cryptojacking and how do you stop it?
Cryptojacking secretly uses your device to mine crypto for someone else. It often hides in browser scripts, bad extensions, or pirated software.
Vahe HakobyanEditor-in-chief
Updated Oct 6, 20263 min readFact-checked
On this page
- Slow, hot devices can point to cryptojacking, but many apps cause similar symptoms.
- Browser mining can run without a download, so scans may miss it.
- Closing tabs, removing extensions, and updating software help stop it.
- Unlike ransomware, cryptojacking hides and steals power.
Attackers want coins without paying for hardware or electricity. The code runs in the background, so you may notice only sluggish or hot performance.
What is cryptojacking?
Cryptojacking is a hidden form of theft. Someone else uses your device to run mining calculations and keeps any coins the mining earns. You did not agree to it, and you usually get nothing.
How do you spot cryptojacking?
Telltale signs include slow performance, high processor use, battery drain, and loud fans. A slow, hot device is not proof, because many ordinary apps cause the same symptoms.
How does cryptojacking get on devices?
It often arrives through malicious sites, browser scripts, bad extensions, or pirated software. A site can run mining code in your browser while the page stays open. In January 2018, Ars Technica reported that YouTube ads contained JavaScript that mined Monero.
How do you remove cryptojacking?
Stop it by closing suspicious tabs, scanning for malware, removing unknown extensions, and updating software. Closing a mining tab usually stops the drain right away. Run a full scan and follow the cleanup steps.
- Close suspicious tabs and windows.
- Run a full malware scan.
- Remove unknown browser extensions.
- Update your operating system, browser, and apps.
Cryptojacking vs. ransomware and web mining
Cryptojacking differs from ransomware: no ransom note, no locked files, just stolen computing power. Consent is the line between legitimate web mining and cryptojacking. Legitimate web mining asks for permission, while cryptojacking does not.
Frequently asked questions
Yes, when it accesses a device without authorization, it can violate computer fraud laws. The E-Sports Entertainment case was later settled with the State of New Jersey.
It can slow down or crash a device by straining its processor. It can also cause overheating and battery wear.
Antivirus can catch malware-based cryptojacking, but browser scripts may run without a downloaded file, so scans can miss them.
You can report it to the FBI's Internet Crime Complaint Center and to your state attorney general. Include dates and any suspicious files or extensions.
