Covert Cryptocurrency Miners Quickly Become A Major Problem

from the lessons-unlearned dept

As websites increasingly struggle to keep the lights on in the age of ad blockers, a growing number of sites have increasingly turned to bitcoin miners like Coinhive. Such miners covertly use visitor CPU cycles to mind cryptocurrency while a user is visiting a website, and actively market themselves as a creative alternative to the traditional advertising model. And while this is certainly a creative revenue generator, these miners are increasingly being foisted upon consumers without informing them or providing an opt out. Given the miners consume user CPU cycles and a modest amount of power -- that's a problem.

The Pirate Bay was forced to disable its bitcoin miner back in September, after users complained it was eating up to 90% of their available CPU cycles. Showtime was similarly caught using a bitcoin miner on two of its domains, and has yet to provide any detail on why it launched the miners or refused to inform visitors they were running. More recently, Trend Micro unveiled that at least two Android apps -- downloaded up to 50,000 times from the Google Play store -- were covertly putting crypto miners inside a hidden browser window:

Recently, we found that apps with malicious cryptocurrency mining capabilities on Google Play. These apps used dynamic JavaScript loading and native code injection to avoid detection. We detect these apps as ANDROIDOS_JSMINER and ANDROIDOS_CPUMINER [...] This JavaScript code runs within the app’s webview, but this is not visible to the user because the webview is set to run in invisible mode by default. When the malicious JavaScript code is running, the CPU usage will be exceptionally high.

The explosion in bitcoin miners is both above and below board. There's indication that the bitcoin miners running on Showtime's domains were the result of a website hack. More recently, researchers from security firm Sucuri discovered that at least 500 websites running WordPress had been hacked, and that other publishing platforms including Magento, Joomla, and Drupal were also being consistently abused. Reddit users this week documented how Choice Hotels (owner of Comfort Inn) websites have also been compromised with cryptocurrency miners the company itself seems oblivious to.

Political fact-checking website PolitiFact also recently acknowledged it was hacked by intruders who installed bitcoin miners that quickly gobbled up visitors' CPU cycles without permission:

Not too surprisingly, security firms like Malwarebytes have started blocking the miners:

The reason we block Coinhive is because there are site owners who do not ask for their users' permission to start running CPU-gorging applications on their systems. A regular Bitcoin miner could be incredibly simple or a powerhouse, depending on how much computing the user running the miner wants to use. The JavaScript version of a miner allows customization of how much mining to do, per user system, but leaves that up to the site owner, who may want to slow down your computer experience to a crawl.

And while these tools help some with malicious installs and hacks, plenty of websites still appear to think it's a good idea to run the miners without notifying users or providing a functioning opt out. Which means there are plenty of folks busy trying to combat the rise of ad blockers -- by engaging in the exact same behavior that caused the rise of ad blockers in the first place.

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Filed Under: coinhive, cryptocurrency, miners