Fans of the Ultimate Fighting Championship (UFC) are complaining on social media that the company is secretly mining cryptocurrency using their systems. Multiple users of the video streaming service UFC Fight Pass report that the video streaming service is running a mining script in the background without their consent.

Join the iFX EXPO Asia and discover your gateway to the Asian Markets

The script appears to be mining one the Darknet’s most favorite cryptocurrencies, Monero.

Available in over 150 countries, UFC Fight Pass is estimated to have about 450,000 subscribers around the world. Subscription costs around $9 per month not including pay-per-view shows, on devices like Apple TV, iPhone, Android, Xbox, Roku, Amazon Fire TV, and Chromecast. In 2016, the UFC’s parent company Zuffa was sold to William Morris Endeavor (WME-IMG) for $4 billion, making it the most expensive sports network acquisition ever.

This is not the first time a website has been accused of trying to monetize its traffic in secret by adding such a cryptocurrency miner. The most recent example is the popular torrent index The Pirate Bay, who admitted of testing out the feature as a way to bring in more revenues. However, the aforementioned monetary success of the UFC and the very low profitability of CPU mining these days makes this very unlikely to be the case.

It is far more likely that a hacker or a rogue employee of the firm (or some third party contractor which manages the service) has injected the script to make some pocket change to fund a little Darknet shopping.

In the meantime, remember to protect your systems by keeping an updated antivirus and firewall software. You never know where a cyber attack can come from.