Norton has updated its advice on VPNFilter, a potentially destructive spyware that can infect over 70 common routers – if not more.

Not surprisingly its new Norton Core is not at risk. But many enterprise and small office/home office routers are at risk. These include (list at the end) Asus, D-Link, Huawei, Linksys, MikroTik, Netgear, TP-Link, Ubiquiti, Upvel, and ZTE. QNAP network-attached storage (NAS) devices are also at risk.

How do you get VPNFilter?

Either the router still has default admin login and passwords or via vulnerabilities. Web bots swarm the internet looking for open doors.

Stage 1 installed a persistent presence on the infected device. It contacts a command and control (C&C) server to download further modules depending on the brand/model.

Stage 2 is the main payload. It is capable of

  • File collection
  • Command execution
  • Data exfiltration
  • Device management
  • A destructive capability to “brick” the device if it receives a command from the attackers. It does this by overwriting a section of the device’s firmware and rebooting, rendering it unusable.

Stage 3 modules include:

  • A packet sniffer for spying on traffic routed through the device for stealing website credentials
  • Monitoring of Modbus SCADA protocols
  • Communicate using Tor

A newly discovered (disclosed on June 6) Stage 3 module called “ssler” can intercept all traffic going through the device via port 80. This means attackers can snoop on web traffic and also tamper with it to perform man-in-the-middle (MitM) attacks.

It can change HTTPS requests to ordinary HTTP requests. Data that is meant to be encrypted is sent insecurely in plain text. This means credentials and other sensitive information is open to hackers. The discovery of this module is significant since it provides the attackers with a means of moving beyond the router and on to the victim’s network.

A fourth Stage 3 module known as “dstr” (disclosed on June 6) adds a kill command to any Stage 2 module which lacks this feature. If executed, dstr will remove all traces of VPNFilter before bricking the device.

The ‘bricking’ destructive capability is interesting. One imagines that hackers will get great pleasure from taking out potentially millions of routers. However, if it is bricked most makers have instructions to reload the OS from a USB drive.

How to get rid of VPNFilter

Stage One is persistent meaning it can withstand rebooting. A hard reset generally removes it.

But it will happen again unless you contact your manufacturer and get the latest firmware to specifically protect the router from this.

GadgetGuy’s take – change admin passwords and hard reset NOW!

Many of the affected brands are well known. They have in common use of similar Linux based router operating systems and chipsets.

If I had a dollar for every time I have seen a router with default login/password, I would be well-off. The reality is that web bots roam the internet looking for unprotected IoT devices and this is just one example.