U.S. Disrupts Russian Botnet of 500,000 Infected Routers

The U.S. Justice Department seized an internet domain that directed a botnet of 500,000 infected home and office network routers, controlled by the Russian hacking group that hit the Democratic National Committee in 2016.

The move was aimed at breaking up an operation embedded in small and medium-sized computer networks and positions the bureau to short-circuit Moscow’s ability to re-infect its targets. The Justice Department said the “VPNFilter” botnet is a piece of sophisticated malware linked to the Russian hacking group, Fancy Bear, and Cisco claims the botnet has infected at least 500,000 devices in at least  54 countries including the United States.

VPN Filter uses known vulnerabilities to infect home office routers made by MikroTik, NETGEAR, and TP-Link. Once in place, the malware reports back to a command-and-control infrastructure that can install purpose built plug-ins. Security researchers claim that one plug-in allows hackers to eavesdrop on a victim’s internet traffic, allowing hackers to compromise website credentials. A second plug-in targets a protocol used in industrial control networks, like those in the electric grid. The third plug-in lets the hacker cripple any or all of the infected devices.

However, the Justice Department has identified a key weakness in the malware; once a victim reboots the infected router, the malicious plugins disappear, and only the core malware code remains. This means that the vulnerability will remain, but the move will allow them more time to identify and intervene in other parts of the network.

In Wednesday’s action, the Justice Department obtained a warrant authorizing the FBI to seize a computer domain that is part of the command and control system of the VPNFilter botnet, in order to “further the investigation and disrupt the ongoing criminal activity”. Both Justice and Cisco said they were releasing details of the malware before having found a strong, permanent fix to the problem. By seizing control of the domains involved in running VPNFilter, it will allow owners of these infected routers a chance to reboot them, forcing them to communicate with the now-neutralized command domain.