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Are Your Office Computers Mining Cryptocurrency?

Microsoft has noticed an uptick in enterprise systems running legitimate, but still potentially unwanted cryptocurrency mining software.

 & Michael Kan Principal Reporter

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Using your office computer for personal use is one thing, but what about installing a cryptocurrency miner? Well, some employees might be doing just that.

In recent months, Microsoft has noticed a number of enterprise systems running coin mining software. One might think that hackers were behind the scheme, but Microsoft found that none of the systems were compromised. Instead, someone—likely an employee—decided to install a coin miner on the enterprise system and reap the rewards, the software giant said in a Tuesday blog post.

In January, Microsoft noticed over 1,800 enterprise machines running legitimate, but potentially unwanted coin mining software, up from just a few hundred systems that Microsoft encountered in October.

Microsoft Enterprise Miners

But it's also no surprise. The value of many cryptocurrencies has ballooned over the past year. In particular, one virtual currency known as Monero can be mined simply by harnessing the CPU power of your computer.

However, generating some digital coin can drag down the machine's performance, which can become problematic when those systems run critical business processes, Microsoft said.

The company hasn't been the only security provider to report the issue. In January, Cisco's Talos group also said it noticed a "large number" of enterprise users running coin mining software on their computers, possibly for their own personal gain.

Both companies said this mining can be trickier to block, since it's technically sanctioned by the employee. Nevertheless, businesses should be mindful of the potential costs, especially if the trend catches on. Microsoft warned that the employee-sponsored cryptocurrency mining may "exponentially" spread to more computers, which can run up an electricity bill.

To stop the activities, Microsoft's Windows Defender can block potentially unwanted programs, including coin miners. But the threat isn't merely limited to employees. The ongoing cryptocurrency craze has also sparked a rise in Trojan malware that can deliver coin miners, too. On average, about 688,000 unique computers will encounter it, according to Microsoft's latest stats.

Microsoft Trojan Miners

Hackers appear to be moving from ransomware to covert cryptocurrency miners, the company added. "These developments indicate widespread cybercriminal interest in coin mining, with various attackers and cybercriminal groups launching attacks," Microsoft said.

Last week, the company's antivirus software stopped an outbreak of coin mining malware in Russia. Apparently, the malicious software may have have arrived as Trojans from file-sharing and internet download programs.

About Our Expert

Michael Kan

Michael Kan

Principal Reporter

My Experience

I've been a journalist for over 15 years. I got my start as a schools and cities reporter in Kansas City and joined PCMag in 2017, where I cover satellite internet services, cybersecurity, PC hardware, and more. I'm currently based in San Francisco, but previously spent over five years in China, covering the country's technology sector.

Since 2020, I've covered the launch and explosive growth of SpaceX's Starlink satellite internet service, writing 600+ stories on availability and feature launches, but also the regulatory battles over the expansion of satellite constellations, fights with rival providers like AST SpaceMobile and Amazon, and the effort to expand into satellite-based mobile service. I've combed through FCC filings for the latest news and driven to remote corners of California to test Starlink's cellular service.

I also cover cyber threats, from ransomware gangs to the emergence of AI-based malware. In 2024 and 2025, the FTC forced Avast to pay consumers $16.5 million for secretly harvesting and selling their personal information to third-party clients, as revealed in my joint investigation with Motherboard.

I also cover the PC graphics card market. Pandemic-era shortages led me to camp out in front of a Best Buy to get an RTX 3000. I'm now following how the AI-driven memory shortage is impacting the entire consumer electronics market. I'm always eager to learn more, so please jump in the comments with feedback and send me tips.

The Best Tech I've Had:

  • My first video game console: a Nintendo Famicom
  • I loved my Sega Saturn despite PlayStation's popularity.
  • The iPod Video I received as a gift in college
  • Xbox 360 FTW
  • The Galaxy Nexus was the first smartphone I was proud to own.
  • The PC desktop I built in 2013, which still works to this day.

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