Cryptojacking 101: What it is and how to spot it

Posted: 31 January 2018 11:17 am


How to make sure your computer isn't being used by someone else for crypto mining.

Producing cryptocurrencies requires lots of computer processing power. And that is driving the cost of computing components up with companies like Nvidia defending the need to increase prices as demand soars, as propel use GPUs for the production of cryptocurrency.

As a result, criminals, keen to enter cryptocurrency markets, are turning to the theft of processing power to drive the creation of more coins.

This theft is called cryptojacking.

It involves the surreptitious operation of software on a user's computer. The software hijacks the computer's processor to harvest cryptocurrency without the owner's permission or knowledge.

Cryptojacking typically occurs in two ways. Either the user is duped into downloading a malicious file, which installs cryptojacking software, such as this recent attack discovered by Palo Alto Networks, or they visit a website that is running malicious code that uses the computer's processor.

These in-browser attacks, like the one that recently affected advertising on YouTube, are especially sneaky as they don't rely on users doing anything other than visiting a website. They use JavaScript and start leaching CPU cycles without any intervention on your part. In some cases, shutting down the browser tab that starts the attack is not enough to stop it as the JavaScript can continue running even if the errant web site is closed.

It's not just computers that are under attack. Loapi is a form of Android malware that uses your smartphone or tablet to mine cryptocurrency. It's thought to be damaging to devices as it can cause devices to overheat, such is the processing grunt they try to extract.

Detecting a cryptojacking attack can be difficult, particularly in the case of in-browser attacks which don't install any files to your computer. The most obvious symptom is excessive CPU utilisation when it's not expected.

If your PC slows down unexpectedly when carrying out simple operations such as reading a text document, check your processor use. You can do that with Task Manager with Windows or Activity Monitor on a Mac.

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