In June 2011,
Symantec warned about the possibility that
botnets could mine covertly for bitcoins. Malware used the
parallel processing capabilities of
GPUs built into many modern
video cards. Although the average PC with an integrated graphics processor is virtually useless for bitcoin mining, tens of thousands of PCs laden with mining malware could produce some results. In mid-August 2011, bitcoin mining botnets were detected, and less than three months later, bitcoin mining
trojans had infected Mac OS X. In April 2013,
electronic sports organization
E-Sports Entertainment was accused of hijacking 14,000 computers to mine bitcoins; the company later settled the case with the State of New Jersey. German police arrested two people in December 2013 who customized existing botnet software to perform bitcoin mining, which police said had been used to mine at least $950,000 worth of bitcoins. For four days in December 2013 and January 2014,
Yahoo! Europe hosted an ad containing bitcoin mining malware that infected an estimated two million computers using a
Java vulnerability. Another software, called
Sefnit, was first detected in mid-2013 and has been bundled with many software packages. Microsoft has been removing the malware through its
Microsoft Security Essentials and other security software. Several reports of employees or students using university or research computers to mine bitcoins have been published. On February 20, 2014, a member of the
Harvard community was stripped of their access to the university's research computing facilities after setting up a
Dogecoin mining operation using a Harvard research network, according to an internal email circulated by Faculty of Arts and Sciences Research Computing officials.
Ars Technica reported in January 2018 that
YouTube advertisements contained
JavaScript code that mined the cryptocurrency
Monero. In 2021,
multiple zero-day vulnerabilities were found on Microsoft Exchange servers, allowing
remote code execution. These vulnerabilities were exploited to mine cryptocurrency. == Detection ==