The Federal Bureau of Investigation moved to dismantle a large network of hacked routers and storage devices that Cisco Systems Inc. and U.S. and Ukraine authorities said could be used to launch a massive cyberattack or knock hundreds of thousands of internet users offline.
The FBI said late Wednesday that it has seized control of the internet domain that was used by the computer network’s “command and control” server to issue instructions to infected devices. The agency said it has begun an effort to clean up the estimated half-million infected devices.
That effort will take some time, security researchers say. Researchers and Ukranian authorities warned earlier that the network could be used by Russia to launch an attack timed to the final match in soccer’s UEFA Champions League competition taking place Saturday in Kiev.
The hacked devices, which span 54 countries, are infected with sophisticated software called VPNFilter that can install other software or even internal changes that render the devices unusable, according to Craig Williams, a security researcher with Cisco CSCO, +0.07% .
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