An engineer from the US state of Missouri, Daniel Rhyne, has been arrested on charges of hacking into the computer system of his former employer, fraud, and extortion of 20 bitcoins worth $750,000.

Daniel Rhine, 57, of Kansas City, was arrested on August 27 after attempting to extort bitcoins from an industrial company headquartered in Somerset County, New Jersey, where Rhine worked as a basic infrastructure engineer.

According to prosecutors, some employees received an email stating that all of the company’s IT administrators had been blocked or removed from the network, and that backup copies of the data had been deleted. The hacker threatened to shut down 40 servers daily for 10 days unless the company paid him 20 BTC.

“The investigation revealed that Ryan had gained unauthorized access to the company’s computer systems. He scheduled several tasks on the network, changed administrator passwords, and shut down the company’s servers. Ryan took control of an email address that he used to send ransomware letters to employees,” the U.S. Department of Justice said.

Prosecutors alleged that Ryan used the PsPasswd tool from Sysinternals Utilities to change domain and administrator accounts.

The defendant appeared in court on the day of his arrest. He faces wire fraud charges and faces a maximum sentence of 35 years in prison and a $750,000 fine.

In June, hackers managed to break into the system of the American educational institution Los Alamos Public Schools and the educational platform Edgenuity. The attackers demanded 30 BTC, threatening to publish confidential data of students and their parents.