Developer gets 4 years for activating network “kill switch” to avenge his firing

Summary

A disgruntled developer has been sentenced to four years in prison after building a "kill switch" that locked all users out of a US firm's network the moment that his name was deleted from the company directory following his termination. Davis Lu, a 55-year-old Chinese national residing in Houston, was convicted of "causing intentional damage to protected computers" in March, the US Department of Justice said in a press release announcing his sentencing Thursday. Lu had worked at Eaton Corp. for approximately 11 years when suddenly the company reduced his responsibilities during a 2018 "realignment." Anticipating his termination was imminent, Lu began planting different forms of malicious code. Some of the malicious code—which Lu named using the Japanese word for destruction, "Hakai," and the Chinese word for lethargy, "HunShui"—created "infinite loops" that deleted coworker profile files, prevented legitimate logins, and caused system crashes, the DOJ said previously. But the most damaging to Eaton Corp. was code that Lu named after himself, "IsDLEnabledinAD," which the DOJ translated as an abbreviation for "Is Davis Lu enabled in Active Directory." That "kill switch" was designed to "lock out all users if his credentials in the company’s active directory were disabled," the DOJ said Thursday. And it worked flawlessly, "automatically activated" when Lu "was placed on leave and asked to surrender his laptop" in 2019. It locked out "thousands of company users globally," and no one had a clue what was going on. Eaton Corp. finally discovered the kill switch while investigating the "infinite loops" that were eventually traced back to a computer using Lu's user ID, a court filing said. That discovery led the company to a server—which only Lu had access to—where all the other malicious code was found. Ultimately, Eaton Corp. bore substantial costs getting its network back online, Matthew Galeotti, acting assistant attorney general of the Justice Department’s criminal div...