Unbeknown to you, your PC may be making money for cryptominers. Unbeknown to you, your PC may be making money for cryptominers.

Cybercriminals are secretly hijacking computers to mine digital currency, Kaspersky Lab warns.

Security experts at the cybersecurity firm have identified a spike in cyberattacks in the recent past aimed at stealing computer power for mining operations. Mining digital currencies is a computationally intensive process that computers comprising a cryptocurrency network complete to verify the transaction record, called the blockchain, and earn digital coins in return.

As the cryptocurrency market heats up, malicious mining software, known as miner, has been actively deployed by criminals in order to make easy money. Kaspersky Lab estimates the year the number of affected users will exceed two million by the end of this year. 

PC users are inadvertently putting themselves at risk by downloading “free” applications that hide the mining software. Kaspersky Lab experts recently identified a number of websites, created using one standard design, which have been offering users free, pirated software such as popular computer programs and applications.

The first sign something is amiss is a PC that seems to be running much slower than usual. At the end of the month, you may receive an electricity bill that is noticeably higher than average.

“Although not considered malicious, mining software decreases the device’s system performance, which inevitably affects the user experience, along with increasing the victim’s electricity bill. As a result, the use of seemingly harmless pirated software leads to the victim - at their own expense - augmenting someone else’s wallet. We advise users to remain vigilant and use legal software to avoid such malicious handouts,” said Alexander Kolesnikov, malware analyst at Kaspersky Lab.