A Houston resident was sentenced to four years in prison on Thursday for intentionally installing malicious code on his employer's computer systems.

Davis Lu, a 55-year-old Chinese national, was convicted in March of causing intentional damage to protected computers. In addition to the four-year sentence, Lu was also given three years of supervised release.

In court documents, prosecutors accused Lu of writing and deploying malicious code in 2018 and 2019 after a corporate restructuring at the Ohio-based company where he had worked since 2007 reduced his role and system access. 

Lu introduced malicious code that he knew would cause system crashes and prevent user logins, according to the DOJ.

According to Cleveland.com, Lu worked for the power management company Eaton Corporation. 

“The defendant breached his employer’s trust by using his access and technical knowledge to sabotage company networks, wreaking havoc and causing hundreds of thousands of dollars in losses for a U.S. company,” said acting assistant Attorney General Matthew Galeotti. 

Lu deleted the system profiles of his coworkers and installed a “kill switch” that would allow him to lock everyone out of the systems if his credentials were ever disabled. 

He named the kill switch code after himself, and it was eventually activated when he was placed on leave in September 2019. The code went into effect when was asked to surrender his laptop, and ultimately impacted thousands of users around the world. 

Prosecutors obtained his internet searches on his final day of access and found Lu was ardently researching methods he could use to escalate his privileges, hide certain processes and quickly delete data — all in an effort to limit his coworkers’ ability to fix the problems he created. 

The charges against Lu carried a maximum of 10 years in prison. His lawyer said in March that he planned to appeal the verdict.