According to the OIG report:
The researcher asserted that he was conducting tests on the computers, but neither university had authorized him to conduct such tests — both university reports noted that the researcher accessed the computer systems remotely and may have taken steps to conceal his activities, including accessing one supercomputer through a mirror site in Europe. … The researcher’s access to all NSF-funded supercomputer resources was terminated. In response to our recommendation, NSF suspended the researcher government-wide.
CoinDesk reports that such abuses are actually on the rise, citing the well-reported case of a Harvard researcher using the university’s 14,000 CPU cluster research computers to mine Dogecoin. Another high-profile case involved an attempt by Iowa State University students to install bitcoin-mining malware on the campus network. In both cases, there were few details about the amount of cryptocurrency mined from the university machines.