Cryptocurrency miners embedded in websites is increasingly becoming a problem for smartphones, but the Opera web browser is trying to remove the threat for its users.

Opera, which already introduced cryptocurrency miner protection in its desktop-based versions, is now putting the same feature into its smartphone browsers, the company announced Monday.

The new feature will be available on Opera Mini and Opera for Android, according to a press release, and is part of the browser's native ad-blocker function.

According to the press release:

Opera estimates that more than a billion devices worldwide are slowed down by website-based cryptocurrency miners that users do not realize are "cryptojacking" their browsers. On the other side of the browsing experience, the company believes there are now more than 3 million websites with embedded cryptocurrency miners.

Making it tricky for users to know there's a problem, there may be no visual cue that a miner is taking advantage of a web browser, according to the firm.

Cryptocurrency miners can overload smartphones' CPUs, forcing 100 percent usage and potentially causing a phone to overheat.

And the damage can sometimes be permanent. According to a ZDNet article, one trojan generated so much heat in a phone, its battery became swollen, permanently damaging the phone. While excessive ads were one reason for the heat generation, the main cause was that the phone's CPU was hijacked to mine for Monero.

The trojan was so effective, it "wrecked the phone within 48 hours," according to the article.

Opera's new feature is already available, and the browser can be downloaded from the Google Play store, according to the release.

Opera image via Shutterstock