The world’s largest oil pipeline operator reportedly had some of its computer systems affected by cryptocurrency mining malware.

Russian pipeline giant Transneft, according to Reuters, recently had to clear malware from its systems that clandestinely mined the privacy-oriented cryptocurrency monero. It’s not clear how many computers were impacted, but Reuters quoted a senior Transneft official who referenced multiple “incidents” during which the malware was discovered.

“Incidents where the company’s hardware was used to manufacture cryptocurrency have been found. It could have a negative impact on the productivity of our processing capacity,” Transneft vice-president Vladimir Rushailo reportedly told company executives during a meeting yesterday.

Transneft said that it has moved to shore up its cybersecurity systems in order to prevent those kinds of malware from being downloaded onto its computer systems.

The pipeline company is one of the most high-profile firms to date to be affected by the malware, which effectively operates in the background of a computer and uses spare capacity to mine cryptocurrencies.

Several notable websites have been impacted in recent months, including a pay-per-view platform for Ultimate Fighting Challenge and an on-demand video service run by Showtime.

According to a cybersecurity report published in October, the CoinHive monero mining software became the sixth-most malware that month.

Pipeline image via Shutterstock