The mining software, made by the company Epic Scale, started appearing for some people earlier this week after they updated to the latest version of uTorrent, a program made by BitTorrent for downloading files. In forums online, users have likened the software to bloatware, as it taxes their computer processor without their consent. Cryptocurrency mining software is used to release bitcoins and other digital currencies by having computers persistently perform complex mathematical calculations.
Some uTorrent users have said their computers were slowing down and overheating due to the software, kicking their fans into overdrive. Others reported persistent pop-ups they couldn't remove, or messages saying their computers were unable to connect to a server.
"When I arrived home this evening my PC was running at full tilt and practically blowing steam," one user wrote on the site for FreeFixer, which makes a tool for removing unwanted software. A thread there has amassed dozens of complaints over the past couple of days.
Users said they received no notification that the software was being installed.
"The only reason I found out about it was that I was playing a game and it was running much slower than usual with constant hiccups," one user wrote.
Users have reported similar complaints in a forum on uTorrent's own site, according to news reports, but those threads have since been removed.
A spokesman for uTorrent maker BitTorrent said there is no silent install happening. Epic Scale is one of many partners that BitTorrent has that might provide installation offers during the install of uTorrent, and the installation is optional, BitTorrent said in a joint blog post with Epic Scale on Friday.
Still, BitTorrent is looking into the issue internally and with Epic Scale, BitTorrent said in the post. The company has received less than a dozen inquiries about the issue over the past 24 hours, the spokesman said.
Epic Scale's software runs only on Windows machines. It's supposed to use the CPU when it's inactive to generate litecoins, an alternative to bitcoins that are worth less but designed to be confirmed more quickly when used for transactions.
Epic Scale wants to put users' computers to work in other areas beyond cryptocurrency and donate money to charities in the process. The company has partnered with research organizations such as the University of California, San Francisco, to help with genomic computations.
Epic Scale did not address the silent download complaints in its post with BitTorrent. But "Epic Scale strongly believes in opt-in installs only," CEO Tim Olson said via email. The company has received about a dozen emails from affected users and is working with BitTorrent to review the claims, he said.
In the FreeFixer thread, an Epic Scale employee acknowledged the problem.
"I recognize many of you are reporting a silent install. We are going to address this with all our distribution partners and determine what's going on (technical or otherwise)," the employee wrote, providing the email address quality@epicscale.com.
In several instances, the employee offered a US$20 Amazon gift card to people experiencing the issue.
Users are having problems removing the software too. Some reported they were able to uninstall the Epic Scale program, while others weren't able to remove all of its components. Other users said they could not even locate the software in their computer's add/remove programs section.
Epic Scale created a new page with instructions for removing for the software on Friday.
It's unclear what caused the issue. At least one user reported everything was fine after downloading the newest version of uTorrent. "You just have to be careful and don't rush the install process," the person wrote in the thread.
Zach Miners covers social networking, search and general technology news for IDG News Service. Follow Zach on Twitter at @zachminers. Zach's e-mail address is zach_miners@idg.com