A Chinese national living in Texas was sentenced on Thursday to four years in prison and three years of supervised release for installing malicious code on his former employer’s systems, including a “kill switch” that locked workers out when his account was disabled.

Davis Lu — a 55-year-old man residing legally in Houston — was convicted in March of intentionally damaging protected computers while working as a software developer for the Ohio-based company, according to a news release from the U.S. Department of Justice.

That “kill switch” was triggered in September 2019 when Lu was placed on leave and told to return his company laptop, instantly shutting out thousands of users worldwide, according to the release.

A U.S. Justice Department logo or seal showing Justice Department headquarters, known as “Main Justice,” is seen behind the podium in the Department’s headquarters briefing room before a news conference with the Attorney General in Washington, January 24, 2023.   (REUTERS/Kevin Lamarque/File Photo)

On the day he was ordered to give back his laptop, Lu also wiped encrypted data from company systems. His search history revealed that he researched how to hide processes, escalate privileges and quickly erase files — suggesting an attempt to slow down recovery efforts, according to the DOJ.

“I am proud of the FBI cyber team’s work which led to today’s sentencing and hope it sends a strong message to others who may consider engaging in similar unlawful activities,” Brett Leatherman, assistant director of the cyber division at the Federal Bureau of Investigation (FBI), said in a statement. “This case also underscores the importance of identifying insider threats early and highlights the need for proactive engagement with your local FBI field office to mitigate risks and prevent further harm.”

The U.S. Department of Justice did not immediately respond to Fox News Digital’s request for comment.