A hacker group has made over $3 million by breaking into Jenkins servers and installing malware that mines the Monero cryptocurrency. Israeli security firm Check Point uncovered the footprint of a large hacking operation targeting Jenkins servers left connected to the Internet. Jenkins is a continuous integration/deployment web application built in Java that allows dev teams to run automated tests and execute various operations based on test results, including deploying new code to production servers. Researchers say the group appears to have compromised mostly Jenkins instances running on Windows operating systems.
Source: https://www.bleepingcomputer.com/news/security/hacker-group-makes-3-million-by-installing-monero-miners-on-jenkins-servers/