The smartphones’ users seem to be as exposed to cryptocurrency mining hijacks as the PC users, and sometimes on an extreme scale. Malwarebytes’ blog posted a “drive-by” mining campaign that managed to redirect millions of Android phone users to a website. This site was hijacking their smartphone processors in order to mine Monero.
The exact trigger was not clear, however, the researchers suspected that apps infected with malicious ads would drive users toward these pages. Surprisingly, the trick was obvious as the website claimed that you were showing suspicious web activity, so it told you it was mining until you typed a captcha code to make it stop.
The number of victims is not known yet, but for sure it’s large. Malwarebytes identified 5 different internet domains that were using the same captcha code as well as Coinhive site keys that were used for the campaign. All the domains together enjoyed about 800k visits daily, and at least 2 of the sites had more than 30 million visits monthly. Although the majority of the users only spent an average of 4 minutes on these sites, this resulted in much mining time.
How do you protect yourselves?
As a result, it’s recommending that Android users use security software and web filters in order to fend off these attacks. Further, you should use only trusted sources for downloading apps such as Google Play or sites that have a good reputation.
Although this hijack is not affecting the cryptocurrency market directly, it’s unlikely that mining tricks like the above-mentioned will disappear anytime soon. As long as cryptocurrency prices remain high, we’re bound to see such kinds of attacks quite often.