Does your laptop get hot when visiting your favorite shop? You computer is likely mining cryptocurrencies to the benefit of a cyberthief.
Cryptojacking - running crypto mining software in the browser of unsuspecting visitors - is quickly spreading around the web. And the landgrab extends to online stores. The infamous CoinHive software was detected today on 2496 e-commerce sites.
Skimming and cryptomining, a golden match
Now, it does not seem likely that the legitimate store owners wanted to earn a few extra bucks and have added CoinHive themselves. I found that 80% of cryptomining stores also contain payment skimming malware. Apparently, cyberthieves are squeezing every penny out of their confiscated assets.
Spread fuelled by just a few individuals
As CoinHive requires a unique ID, we can analyze the distribution of crypto thieves. Out of 2496 infected stores, 85% is linked to only 2 CoinHive accounts, while the remaining 15% is spread out over unique CoinHive accounts. Because the tag added to this remaining 15% segment is consistenly the site’s name, my guess is that this cryptojacking surge on online stores can be attributed to just 3 individuals or groups.
Some sites bluntly include the official coinhive.js file, others are more stealthy and include an iframe that points to siteverification.online. This site shows a default Debian installation page but include a cryptominer nevertheless. Yet others disguise as Sucuri Firewall.
Fix for your browser
I have added detection signatures to the open source Magento Malware Scanner