The U.S. Justice Department said on Tuesday that it has deleted malware planted on more than 4,200 computers by a group of criminal hackers who were backed by the People’s Republic of China. From a report: The malware, known as “PlugX,” affected thousands of computers around the globe and was used to infect and steal information, the department said. Investigators said the malware was installed by a band of hackers who are known by the names “Mustang Panda” and “Twill Typhoon.”