The Justice Department announced Tuesday that it had disrupted a sprawling malware network used by Russia’s Federal Security Service (FSB) to steal sensitive data from the U.S. and its allies over more than two decades. The “sophisticated” malware, codenamed Snake, was developed as far back as 2004 and attributed to Turla, a hacking unit within the FSB. It gave Russian agents clandestine access to hundreds of computer systems in at least 50 countries, including several NATO-member governments, according to a department news release. Snake was also used to spy on journalists and other Russian “targets of interest.” With the cooperation of other foreign governments, American researchers and counterintelligence agents used an FBI-created tool called Perseus to issue “commands that caused the Snake malware to overwrite its own vital components.” The takedown effort by U.S. law enforcement, known as Operation Medusa, dismantled the malware “on or about May 8,” authorities said.