Texas Man Convicted of Sabotaging his Employer’s Computer Systems and Deleting Data

A federal jury in Cleveland convicted a Texas man today for writing and deploying malicious code on his former employer’s network.

According to court documents and evidence presented at trial, Davis Lu, 55, of Houston, 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 and 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 upon his termination on Sept. 9, 2019, and impacted thousands of company users globally. Lu named other code “Hakai,” a Japanese word meaning “destruction,” and “HunShui,” a Chinese word meaning “sleep” or “lethargy.” Additionally, on the day he was directed to turn in his company laptop, Lu deleted encrypted data. His internet search history revealed he had researched methods to escalate privileges, hide processes, and rapidly delete files, indicating an intent to obstruct efforts of his co-workers to resolve the system disruptions. Lu’s employer suffered hundreds of thousands of dollars in losses as a result of Lu’s actions.

The jury convicted Lu of causing intentional damage to protected computers, for which he faces a maximum penalty of 10 years in prison. A sentencing date has not been set. A federal district court judge will determine any sentence after considering the U.S. Sentencing Guidelines and other statutory factors.

Supervisory Official Matthew R. Galeotti of the Justice Department’s Criminal Division, Acting U.S. Attorney Carol M. Skutnik for the Northern District of Ohio, and Special Agent in Charge Gregory D. Nelsen of the FBI Cleveland Field Office made the announcement.

The FBI Cleveland Field Office investigated the case.

Senior Counsel Candina S. Heath of the Criminal Division’s Computer Crime and Intellectual Property Section and Assistant U.S. Attorneys Daniel J. Riedl and Brian S. Deckert for the Northern District of Ohio are prosecuting the case.