Most of the security write-ups you see online deal with software. It’s true that you’re far more likely to encounter some sort of software-based security threat than any of the hardware threats to date. However, ignoring hardware threats can be problematic. Unlike the vast majority of software threats that you can clean up, hardware threats often damage a system so that it becomes unusable. You literally have to buy a new system because repair isn’t feasible (at least, for a reasonable price).
The threats are becoming more ingenious too. Consider the USB flash drive threat called USB Killer. In this case, inserting the wrong thumb drive into your system can cause the system to completely malfunction. The attack is ingenious in that your system continues to work as normal until that final moment when it’s too late to do anything about the threat. Your system is fried by high voltage sent to it by the thumb drive. Of course, avoiding the problem means using only thumb drives that you can verify are clean. You really can’t even trust the thumb drive provided by friends because they could have obtained the thumb drive from a contaminated source. The result of such an attack is lost data, lost time, and lost hardware—potentially making the attack far more expensive than a software attack on your system.
Some of the hardware-based threats are more insidious. For example, the Rowhammer vulnerability makes it possible for someone to escalate their privileges by accessing the DRAM on your system in a specific way. The technical details aren’t quite as important as the fact that it can be done in this case because even with repairs, memory will continue to be vulnerable to attack in various ways. The problem is that memory has become so small that protections that used to work well no longer work at all. In addition, hardware vendors often use the least expensive memory available to keep prices low, rather than use higher end (and more expensive) memory.
It’s almost certain that you’ll start to see more hardware threats on the horizon because of the way in which people work with electronics today. All these new revelations remind me of the floppy disk viruses of days past. People would pass viruses back and forth by trading floppies with each other. Some of these viruses would infect the boot sector of the system hard drive, making it nearly impossible to remove. As people start using thumb drives and other removable media to exchange data in various ways, you can expect to see a resurgence of this sort of attack.
The potential for hardware-based attacks continues to increase as the computing environment becomes more and more commoditized and people’s use of devices continues to change. It’s the reason I wrote Does Your Hardware Spy On You? and the reason I’m alerting you to the potential for hardware-based attacks in this post. You need to be careful how you interact with others when exchanging bits of seemingly innocent hardware. Let me know your thoughts about hardware-based attacks at [email protected].
