A Chinese national residing in Texas received a four-year prison sentence and a subsequent three years of supervised release on Thursday. This sentencing followed his conviction for embedding malicious software into his former employer’s systems, which included a “kill switch” that blocked access when his account was deactivated.

Living legally in Houston, Davis Lu, 55, was found guilty in March for deliberately damaging protected computers while employed as a software developer for an Ohio-based firm, as stated in a press release by the U.S. Department of Justice.

The activation of the “kill switch” occurred in September 2019, coinciding with Lu being placed on leave and instructed to return his company laptop, which immediately barred thousands of users around the globe from accessing the system, according to the release.

On the day he was required to surrender his laptop, Lu also erased encrypted data from company systems. His internet history demonstrated that he explored methods to conceal processes, enhance system privileges, and rapidly delete files—indicating a strategy to obstruct recovery efforts, as per 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.