A former engineer at a U.S.-based e-commerce firm, Digital River, has been sentenced to three years of probation after admitting to using his former employer’s cloud servers to secretly mine Ethereum. Court documents show that 45-year-old Joshua Paul Armbrust pleaded guilty in April to a felony count of computer fraud, following an investigation by the U.S. Attorney’s Office for the District of Minnesota.
Armbrust, who resigned from Digital River in February 2020, continued accessing the company’s Amazon Web Services (AWS) account between December 2020 and May 2021. Prosecutors said he repeatedly ran mining programs without authorisation, using the company’s computing power to generate cryptocurrency for personal gain. The Department of Justice stated that his actions incurred more than $45,000 in cloud fees for the company while earning him roughly $5,800 worth of Ethereum.
According to the sentencing announcement by U.S. District Judge Jerry Blackwell, Armbrust was also ordered to repay the full amount of losses to Digital River. Prosecutors described the scheme as a deliberate and sustained misuse of corporate resources, emphasizing that his activity ran nightly between 6 p.m. and 7 a.m. and disrupted company operations.
Defence attorney William J. Mauzy argued that Armbrust acted out of “financial desperation and emotional distress” while caring for his terminally ill mother. He noted that Armbrust did not attempt to hide his activity and had taken responsibility for the financial damage. Mauzy insisted that his client was “not a malicious hacker,” but someone driven by hardship rather than intent to deceive.
The U.S. Attorney’s Office defined the case as an example of “cryptojacking”—a cybercrime where individuals exploit another party’s computing infrastructure to mine digital currencies without consent. The practice, though increasingly common during crypto’s proof-of-work era, often results in substantial energy consumption and operational costs for victims.
At the time of Armbrust’s actions, Ethereum still relied on a proof-of-work consensus mechanism that demanded significant computing resources before transitioning to proof-of-stake in September 2022. Investigators said his mining activity directly contributed to Digital River’s mounting operational costs during a financially strained period.
Digital River has since faced broader financial turmoil, filing for insolvency for its German subsidiaries in January after losing access to a major credit facility. The company has shuttered its Minnesota headquarters and is in the process of winding down operations globally.
Federal prosecutors said Armbrust’s case serves as a warning to employees and corporations about the risks of unauthorised crypto mining. While Armbrust avoided prison time, his sentence underscores the growing seriousness with which U.S. authorities treat cryptojacking and misuse of enterprise cloud infrastructure.
