A suspected nation-state sponsored hacking group has succeeded in infecting at least half a million routers with VPNFilter malware.
VPNFilter is a modular malware capable of various functions, including the monitoring of all communications, launching attacks on other devices, theft of credentials and data, and even destroying the router on which the malware has been installed. While most IoT malware infections – including those used to build large botnets for DDoS attacks – are not capable of surviving a reboot, VPNFilter malware can survive such a reset.
The malware can be installed on the type of routers often used by small businesses and consumers such as those manufactured by Netgear, Linksys, TP-Link and MikroTik, as well as network-attached storage (NAS) devices from QNAP, according to security researchers at Cisco Talos who have been monitoring infections over the past few months.
The ultimate aim of the attackers is unknown, although the infected devices could potentially be used for a wide range of malicious activities, including major cyberattacks on critical infrastructure, such as disrupting power grids – as was the case with BlackEnergy malware.
Since it is possible for the malware to disable Internet access, the threat actors behind the campaign could easily prevent large numbers of individuals in a targeted region from going online.
While the malware has been installed on routers around the world – infections have been detected in 54 countries – the majority of infections are in Ukraine. Infections in Ukraine have increased significantly in the past few weeks.
While the investigation into the campaign is ongoing, the decision was taken to go public due to a massive increase in infected devices over the past three weeks, together with the incorporation of advanced capabilities which have made the malware a much more significant threat.
While the researchers have not pointed the finger at Russia, they have identified parts of the code which are identical to that used in BlackEnergy malware, which was used in several attacks in Ukraine. BlackEnergy has been linked to Russia by some security researchers. BlackEnergy malware has been used by other threat actors not believed to be tied to Russia to the presence of the same code in both forms of malware is not concrete proof of any link to Russia.
The FBI has gone a step further by attributing the malware campaign to the hacking group Fancy Bear (APT28/Pawn Storm) which has links to the Russian military intelligence agency GRU. Regardless of any nation-state backing, the sophisticated nature of the malware means it is the work of a particularly advanced hacking group.
Most of the attacked routers are aging devices that have not received firmware updates to correct known flaws and many of the attacked devices have not had default passwords changed, leaving them vulnerable to attack. It is not entirely clear exactly how devices are being infected although the exploitation of known vulnerabilities is most probable, rather than the use of zero-day exploits; however, the latter has not been ruled out.
Some progress has been made disrupting the VPNFilter malware campaign. The FBI has seized and sinkholed a domain used by the malware to communicate with the threat group behind the campaign. Without that domain, the attackers cannot control the infected routers and neither identify new devices that have been infected.
Ensuring a router is updated and has the latest firmware will offer some degree of protection, as will changing default passwords on vulnerable devices. Unfortunately, it is not easy to tell if a vulnerable router has been infected. Performing a factory reset of a vulnerable router is strongly recommended as a precaution.
Rebooting the device will not eradicate the malware, but it will succeed in removing some of the additional code downloaded to the device. However, those additional malware components could be reinstalled once contact is re-established with the device.