Chinese national who deployed ‘kill switch’ code on employer’s network sentenced to four years in prison

A Chinese national was sentenced on August 21 to four years in prison and three years of supervised release for writing and deploying malicious code on his then-employer’s network. 

“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 R. Galeotti of the Justice Department’s Criminal Division. “However, the defendant’s technical savvy and subterfuge did not save him from the consequences of his actions. The Criminal Division is committed to identifying and prosecuting those who attack U.S. companies, whether from within or without, to hold them responsible for their actions.”  

According to court documents and evidence presented at trial, Lu was employed as a software developer for the victim company headquartered in Beachwood, Ohio, from November 2007 to October 2019. Following a 2018 corporate realignment that reduced his responsibilities and system access, Lu began sabotaging his employer’s systems. By Aug. 4, 2019, he introduced malicious code that caused system crashes and prevented user logins. Specifically, he created “infinite loops” (in this case, code designed to exhaust Java threads by repeatedly creating new threads without proper termination, resulting in server crashes or hangs), deleted coworker profile files, and implemented a “kill switch” that would lock out all users if his credentials in the company’s active directory were disabled. The “kill switch” code — which Lu named “IsDLEnabledinAD”, abbreviating “Is Davis Lu enabled in Active Directory” — was automatically activated when he was placed on leave and asked to surrender his laptop on Sept. 9, 2019, and impacted thousands of company users globally.

Read more at Department of Justice