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SANS ISC: The Internet of Things: How do you "on-board" devices? - Internet Security | DShield SANS ISC InfoSec Forums


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The Internet of Things: How do you "on-board" devices?

Certified pre-pw0ned devices are nothing new. We talked years ago about USB picture frames that came with malware pre-installed. But for the most part, the malware was added to the device accidentally, or for example by customers who later returned the device just to have it resold without adequately resetting/wiping the device.

But more recently, more evidence emerged that everything from network gear [1] to inventory scanners [2] may be infected deliberately in order to penetrate otherwise hard to reach networks. Typically, there is little a customer can do to verify that a device is not infected. Standard practices, like malware scanners and verifying installed software doesn't always work if you don't have "shell access" or the ability to install software on the device. 

This leaves careful network monitoring as one option to  detect and disrupt command and control channels used by these devices. However, in order to do so accurately, it is important to characterize "normal" network traffic from the device, which can be challenging in particular if the device connects to cloud services for updates or intentional data exchange.

The large number of these devices entering our networks asks for a scalable solution. We can't add security devices and personal proportional to the number of devices deployed. The security features included in these devices (host based firewalls, encryption technologies, ability to manage and limit installed software/"apps") varies widely and frequently there are no enterprise configuration tools available. 

What kind of network segmentation and on-boarding procedure do you apply to new devices introduced into the network? 

[1] http://arstechnica.com/tech-policy/2014/05/photos-of-an-nsa-upgrade-factory-show-cisco-router-getting-implant/
[2] http://www.trapx.com/news/press/trapx-discovers-zombie-zero-advanced-persistent-malware/

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Johannes B. Ullrich, Ph.D.
STI|Twitter|LinkedIn

I will be teaching next: Defending Web Applications Security Essentials - SANS Munich July 2019

Johannes

3537 Posts
ISC Handler
I agree that this is becoming more of a problem as everything seems to be connected nowadays, thanks to the "Internet Of Things". I recently checked my home WiFi network and it has somehow grown to about 15 devices. There's not much that ordinary users can do to protect themselves from malware because as you pointed out, the malware is many times already "baked in" to the firmware/software.

I am considering creating a second WiFi network (my router can support 2 plus a guest network) for my IOT devices and using my primary network for my computers and laptops. At least this way, if someone hacks an IOT device, they won't be able to sniff my "normal" internet activity... banking... email... etc.

Establishing a network baseline and monitoring for odd activity is a great thing to do, but I think creating a second network for less secure devices and less critical/sensitive traffic is a good idea as well.
da1212

69 Posts
I was also considering adding another wifi network. Even though right now I leverage the guest feature of my router, I want more separation. I was going to start by dusting off an older wifi (supports WPA2) and make that the guest wifi uplinked through the current router with lan port segregation. I thought of separation by function as well with more hardware. Entertainment and general browsing from financial and other sensitive with separate clients as well.
G.Scott H.

48 Posts

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